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LeetCode-in-Kotlin

Maven Central MIT License Java CI with Maven Maintainability Rating javadoc

Kotlin Solution for LeetCode algorithm problems, continually updating.

Installation

Include the following in your pom.xml for Maven:

<dependencies>
  <dependency>
    <groupId>com.github.javadev</groupId>
    <artifactId>leetcode-in-kotlin</artifactId>
    <version>1.11</version>
  </dependency>
  ...
</dependencies>

Gradle:

implementation 'com.github.javadev:leetcode-in-kotlin:1.11'

"For coding interview preparation, LeetCode is one of the best online resource providing a rich library of more than 300 real coding interview questions for you to practice from using one of the 7 supported languages - C, C++, Java, Python, C#, JavaScript, Ruby."

SQL I

Day 1 Select
0595 Big Countries Easy Database 417 56.09
0584 Find Customer Referee Easy Database 779 43.48
0183 Customers Who Never Order Easy Database 712 33.67

Day 2 Select and Order
0627 Swap Salary Easy Database 400 51.04
0196 Delete Duplicate Emails Easy Database 593 94.17

Day 3 String Processing Functions

Day 4 Union and Select
0608 Tree Node Medium LeetCode_Curated_SQL_70, Database 794 48.38
0176 Second Highest Salary Medium Database 219 92.54

Day 5 Union
0175 Combine Two Tables Easy Database 473 54.97

Day 6 Union
0197 Rising Temperature Easy Database 394 94.15
0607 Sales Person Easy LeetCode_Curated_SQL_70, Database 2142 44.56

Day 7 Function

Day 8 Function
0586 Customer Placing the Largest Number of Orders Easy LeetCode_Curated_SQL_70, Database 768 44.85
0511 Game Play Analysis I Easy LeetCode_Curated_SQL_70, Database 790 45.04

Day 9 Control of Flow

Day 10 Where
0182 Duplicate Emails Easy Database 396 68.40

Level 1

Day 1 Prefix Sum
0724 Find Pivot Index Easy Array, Prefix_Sum 255 88.92

Day 2 String
0205 Isomorphic Strings Easy String, Hash_Table 278 79.96
0392 Is Subsequence Easy String, Dynamic_Programming, Two_Pointers 156 87.74

Day 3 Linked List
0021 Merge Two Sorted Lists Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion 176 96.25
0206 Reverse Linked List Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion 279 45.78

Day 4 Linked List
0876 Middle of the Linked List Easy Two_Pointers, Linked_List 136 76.52
0142 Linked List Cycle II Medium Top_100_Liked_Questions, Hash_Table, Two_Pointers, Linked_List 192 63.39

Day 5 Greedy
0121 Best Time to Buy and Sell Stock Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 609 94.06
0409 Longest Palindrome Easy String, Hash_Table, Greedy 259 60.71

Day 6 Tree
0589 N-ary Tree Preorder Traversal Easy Depth_First_Search, Tree, Stack 233 84.02
0102 Binary Tree Level Order Traversal Medium Top_100_Liked_Questions, Top_Interview_Questions, Breadth_First_Search, Tree, Binary_Tree 332 67.53

Day 7 Binary Search
0704 Binary Search Easy Array, Binary_Search 261 77.91
0278 First Bad Version Easy Binary_Search, Interactive 349 76.86

Day 8 Binary Search Tree
0098 Validate Binary Search Tree Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 330 41.38
0235 Lowest Common Ancestor of a Binary Search Tree Easy Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 404 75.59

Day 9 Graph/BFS/DFS
0733 Flood Fill Easy Array, Depth_First_Search, Breadth_First_Search, Matrix 230 97.76
0200 Number of Islands Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find 252 95.41

Day 10 Dynamic Programming
0509 Fibonacci Number Easy Dynamic_Programming, Math, Recursion, Memoization 139 82.72
0070 Climbing Stairs Easy Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Memoization 127 97.06

Day 11 Dynamic Programming
0746 Min Cost Climbing Stairs Easy Array, Dynamic_Programming 171 96.76
0062 Unique Paths Medium Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Combinatorics 209 49.18

Day 12 Sliding Window/Two Pointer
0438 Find All Anagrams in a String Medium Top_100_Liked_Questions, String, Hash_Table, Sliding_Window 561 54.68
0424 Longest Repeating Character Replacement Medium String, Hash_Table, Sliding_Window 288 84.38

Day 13 Hashmap
0001 Two Sum Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table 234 92.75
0299 Bulls and Cows Medium String, Hash_Table, Counting 254 84.82

Day 14 Stack
0844 Backspace String Compare Easy String, Two_Pointers, Stack, Simulation 126 98.31
0394 Decode String Medium Top_100_Liked_Questions, String, Stack, Recursion 224 64.86

Day 15 Heap
0692 Top K Frequent Words Medium String, Hash_Table, Sorting, Heap_Priority_Queue, Counting, Trie, Bucket_Sort 239 81.10

Level 2

Day 1 Implementation/Simulation
0202 Happy Number Easy Top_Interview_Questions, Hash_Table, Math, Two_Pointers 261 45.08
0054 Spiral Matrix Medium Top_Interview_Questions, Array, Matrix, Simulation 224 62.50

Day 2 String
0014 Longest Common Prefix Easy Top_Interview_Questions, String 209 88.86
0043 Multiply Strings Medium String, Math, Simulation 390 56.25

Day 3 Linked List
0019 Remove Nth Node From End of List Medium Top_100_Liked_Questions, Top_Interview_Questions, Two_Pointers, Linked_List 180 91.58
0234 Palindrome Linked List Easy Top_100_Liked_Questions, Top_Interview_Questions, Two_Pointers, Stack, Linked_List, Recursion 641 79.53

Day 4 Linked List
0328 Odd Even Linked List Medium Top_Interview_Questions, Linked_List 216 86.96
0148 Sort List Medium Top_100_Liked_Questions, Top_Interview_Questions, Sorting, Two_Pointers, Linked_List, Divide_and_Conquer, Merge_Sort 820 61.70

Day 5 Greedy
0621 Task Scheduler Medium Array, Hash_Table, Sorting, Greedy, Heap_Priority_Queue, Counting 266 98.36

Day 6 Tree
0226 Invert Binary Tree Easy Top_100_Liked_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 233 54.90
0110 Balanced Binary Tree Easy Depth_First_Search, Tree, Binary_Tree 310 63.63

Day 7 Tree
0543 Diameter of Binary Tree Easy Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree 307 43.93
0437 Path Sum III Medium Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree 403 54.12

Day 8 Binary Search
0074 Search a 2D Matrix Medium Top_100_Liked_Questions, Array, Binary_Search, Matrix 290 40.17
0033 Search in Rotated Sorted Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search 184 86.08

Day 9 Binary Search Tree
0108 Convert Sorted Array to Binary Search Tree Easy Top_Interview_Questions, Array, Tree, Binary_Tree, Binary_Search_Tree, Divide_and_Conquer 334 35.39
0230 Kth Smallest Element in a BST Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 393 33.33
0173 Binary Search Tree Iterator Medium Tree, Binary_Tree, Stack, Design, Binary_Search_Tree, Iterator 563 46.91

Day 10 Graph/BFS/DFS
0994 Rotting Oranges Medium Array, Breadth_First_Search, Matrix 308 57.93
0417 Pacific Atlantic Water Flow Medium Array, Depth_First_Search, Breadth_First_Search, Matrix 319 100.00

Day 11 Graph/BFS/DFS
0210 Course Schedule II Medium Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Graph, Topological_Sort 266 96.32
0815 Bus Routes Hard Array, Hash_Table, Breadth_First_Search 429 100.00

Day 12 Dynamic Programming
0198 House Robber Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 156 92.24
0322 Coin Change Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Breadth_First_Search 332 50.68

Day 13 Dynamic Programming
0416 Partition Equal Subset Sum Medium Top_100_Liked_Questions, Array, Dynamic_Programming 204 98.82
0152 Maximum Product Subarray Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 253 88.42

Day 14 Sliding Window/Two Pointer
0003 Longest Substring Without Repeating Characters Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Sliding_Window 258 91.09
0016 3Sum Closest Medium Array, Sorting, Two_Pointers 413 95.05
0076 Minimum Window Substring Hard Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Sliding_Window 346 85.20

Day 15 Tree
0100 Same Tree Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 208 72.24
0101 Symmetric Tree Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 190 91.36
0199 Binary Tree Right Side View Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 194 92.89

Day 16 Design
0232 Implement Queue using Stacks Easy Stack, Design, Queue 258 70.86
0155 Min Stack Easy Top_100_Liked_Questions, Top_Interview_Questions, Stack, Design 331 84.88
0208 Implement Trie (Prefix Tree) Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Design, Trie 689 61.00

Day 17 Interval
0057 Insert Interval Medium Array 257 99.52
0056 Merge Intervals Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting 320 94.22

Day 18 Stack
0735 Asteroid Collision Medium Array, Stack 243 100.00
0227 Basic Calculator II Medium Top_Interview_Questions, String, Math, Stack 383 62.50

Day 19 Union Find
0547 Number of Provinces Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find 229 79.73

Day 20 Brute Force/Backtracking
0039 Combination Sum Medium Top_100_Liked_Questions, Array, Backtracking 317 86.85
0046 Permutations Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Backtracking 186 100.00

Udemy

Udemy Integers
0412 Fizz Buzz Easy Top_Interview_Questions, String, Math, Simulation 307 71.81
0136 Single Number Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Bit_Manipulation 344 83.63
0007 Reverse Integer Medium Top_Interview_Questions, Math 245 60.32
0009 Palindrome Number Easy Math 238 96.24
0172 Factorial Trailing Zeroes Medium Top_Interview_Questions, Math 220 67.65
0050 Pow(x, n) Medium Top_Interview_Questions, Math, Recursion 264 52.98

Udemy Strings
0344 Reverse String Easy Top_Interview_Questions, String, Two_Pointers, Recursion 445 69.75
0014 Longest Common Prefix Easy Top_Interview_Questions, String 209 88.86
0187 Repeated DNA Sequences Medium String, Hash_Table, Bit_Manipulation, Sliding_Window, Hash_Function, Rolling_Hash 319 79.03
0003 Longest Substring Without Repeating Characters Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Sliding_Window 258 91.09
0020 Valid Parentheses Easy Top_100_Liked_Questions, Top_Interview_Questions, String, Stack 226 72.53
0005 Longest Palindromic Substring Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming 323 75.48
0394 Decode String Medium Top_100_Liked_Questions, String, Stack, Recursion 224 64.86
0242 Valid Anagram Easy Top_Interview_Questions, String, Hash_Table, Sorting 251 87.65
0049 Group Anagrams Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, String, Hash_Table, Sorting 506 86.55
0151 Reverse Words in a String Medium String, Two_Pointers 206 98.90
0273 Integer to English Words Hard String, Math, Recursion 273 82.93

Udemy Binary Search
0704 Binary Search Easy Array, Binary_Search 261 77.91
0033 Search in Rotated Sorted Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search 184 86.08
0153 Find Minimum in Rotated Sorted Array Medium Top_100_Liked_Questions, Array, Binary_Search 262 60.96

Udemy Arrays
0121 Best Time to Buy and Sell Stock Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 609 94.06
0283 Move Zeroes Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Two_Pointers 516 79.07
0001 Two Sum Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table 234 92.75
0217 Contains Duplicate Easy Top_Interview_Questions, Array, Hash_Table, Sorting 719 73.49
0058 Length of Last Word Easy String 243 63.33
0605 Can Place Flowers Easy Array, Greedy 209 85.71
0122 Best Time to Buy and Sell Stock II Medium Top_Interview_Questions, Array, Dynamic_Programming, Greedy 197 95.10
0080 Remove Duplicates from Sorted Array II Medium Array, Two_Pointers 357 44.78
0189 Rotate Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Math, Two_Pointers 483 86.95
0055 Jump Game Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Greedy 670 66.67
0075 Sort Colors Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Two_Pointers 198 85.66
0066 Plus One Easy Top_Interview_Questions, Array, Math 303 35.18
0238 Product of Array Except Self Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Prefix_Sum 669 48.96
0448 Find All Numbers Disappeared in an Array Easy Array, Hash_Table 394 100.00
0442 Find All Duplicates in an Array Medium Array, Hash_Table 480 73.81
0041 First Missing Positive Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table 345 100.00
0697 Degree of an Array Easy Array, Hash_Table 289 84.62
0532 K-diff Pairs in an Array Medium Array, Hash_Table, Sorting, Binary_Search, Two_Pointers 230 84.62
0713 Subarray Product Less Than K Medium Array, Sliding_Window 336 92.11
0456 132 Pattern Medium Array, Binary_Search, Stack, Ordered_Set, Monotonic_Stack 434 100.00
0239 Sliding Window Maximum Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Heap_Priority_Queue, Sliding_Window, Queue, Monotonic_Queue 1059 86.14

Udemy Two Pointers
0392 Is Subsequence Easy String, Dynamic_Programming, Two_Pointers 156 87.74
0125 Valid Palindrome Easy Top_Interview_Questions, String, Two_Pointers 353 52.06
0026 Remove Duplicates from Sorted Array Easy Top_Interview_Questions, Array, Two_Pointers 361 77.19
0042 Trapping Rain Water Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Two_Pointers, Stack, Monotonic_Stack 196 100.00
0015 3Sum Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Two_Pointers 761 90.55

Udemy Famous Algorithm
0053 Maximum Subarray Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Divide_and_Conquer 662 82.48
0169 Majority Element Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Sorting, Counting, Divide_and_Conquer 460 51.25

Udemy Sorting Algorithms

Udemy 2D Arrays/Matrix
0304 Range Sum Query 2D - Immutable Medium Array, Matrix, Design, Prefix_Sum 1373 85.71
0074 Search a 2D Matrix Medium Top_100_Liked_Questions, Array, Binary_Search, Matrix 290 40.17
0054 Spiral Matrix Medium Top_Interview_Questions, Array, Matrix, Simulation 224 62.50
0048 Rotate Image Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Math, Matrix 287 46.50
0073 Set Matrix Zeroes Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Matrix 255 100.00
0056 Merge Intervals Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting 320 94.22

Udemy Linked List
0114 Flatten Binary Tree to Linked List Medium Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree, Stack, Linked_List 191 93.10
0445 Add Two Numbers II Medium Math, Stack, Linked_List 240 82.61
0328 Odd Even Linked List Medium Top_Interview_Questions, Linked_List 216 86.96
0061 Rotate List Medium Two_Pointers, Linked_List 193 92.16
0024 Swap Nodes in Pairs Medium Top_100_Liked_Questions, Linked_List, Recursion 149 99.39
0876 Middle of the Linked List Easy Two_Pointers, Linked_List 136 76.52
0142 Linked List Cycle II Medium Top_100_Liked_Questions, Hash_Table, Two_Pointers, Linked_List 192 63.39
0141 Linked List Cycle Easy Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Two_Pointers, Linked_List 223 91.85
0206 Reverse Linked List Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion 279 45.78
0021 Merge Two Sorted Lists Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion 176 96.25
0160 Intersection of Two Linked Lists Easy Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Two_Pointers, Linked_List 262 83.50
0234 Palindrome Linked List Easy Top_100_Liked_Questions, Top_Interview_Questions, Two_Pointers, Stack, Linked_List, Recursion 641 79.53
0138 Copy List with Random Pointer Medium Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Linked_List 274 80.58
0025 Reverse Nodes in k-Group Hard Top_100_Liked_Questions, Linked_List, Recursion 194 87.72
0146 LRU Cache Medium Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Design, Linked_List, Doubly_Linked_List 1116 97.93
0707 Design Linked List Medium Design, Linked_List 243 100.00

Udemy Tree Stack Queue
0144 Binary Tree Preorder Traversal Easy Depth_First_Search, Tree, Binary_Tree, Stack 277 37.90
0094 Binary Tree Inorder Traversal Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Stack 269 38.80
0145 Binary Tree Postorder Traversal Easy Depth_First_Search, Tree, Binary_Tree, Stack 211 80.00
0102 Binary Tree Level Order Traversal Medium Top_100_Liked_Questions, Top_Interview_Questions, Breadth_First_Search, Tree, Binary_Tree 332 67.53
0103 Binary Tree Zigzag Level Order Traversal Medium Top_Interview_Questions, Breadth_First_Search, Tree, Binary_Tree 316 34.25
0108 Convert Sorted Array to Binary Search Tree Easy Top_Interview_Questions, Array, Tree, Binary_Tree, Binary_Search_Tree, Divide_and_Conquer 334 35.39
0543 Diameter of Binary Tree Easy Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree 307 43.93
0100 Same Tree Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 208 72.24
0226 Invert Binary Tree Easy Top_100_Liked_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 233 54.90
0111 Minimum Depth of Binary Tree Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 525 90.51
0104 Maximum Depth of Binary Tree Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 236 83.39
0110 Balanced Binary Tree Easy Depth_First_Search, Tree, Binary_Tree 310 63.63
0701 Insert into a Binary Search Tree Medium Tree, Binary_Tree, Binary_Search_Tree 311 79.03
0297 Serialize and Deserialize Binary Tree Hard Top_Interview_Questions, String, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Design 475 78.85
0124 Binary Tree Maximum Path Sum Hard Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Depth_First_Search, Tree, Binary_Tree 331 74.42
0098 Validate Binary Search Tree Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 330 41.38
0337 House Robber III Medium Dynamic_Programming, Depth_First_Search, Tree, Binary_Tree 282 84.62
0236 Lowest Common Ancestor of a Binary Tree Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree 386 45.21

Udemy Trie and Heap
0208 Implement Trie (Prefix Tree) Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Design, Trie 689 61.00
0745 Prefix and Suffix Search Hard String, Design, Trie 1638 100.00

Udemy Graph
0200 Number of Islands Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find 252 95.41
0133 Clone Graph Medium Hash_Table, Depth_First_Search, Breadth_First_Search, Graph 351 60.91
0417 Pacific Atlantic Water Flow Medium Array, Depth_First_Search, Breadth_First_Search, Matrix 319 100.00

Udemy Dynamic Programming
0120 Triangle Medium Array, Dynamic_Programming 194 97.87
0118 Pascal's Triangle Easy Top_Interview_Questions, Array, Dynamic_Programming 277 33.22
0119 Pascal's Triangle II Easy Array, Dynamic_Programming 157 97.27
0139 Word Break Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Dynamic_Programming, Trie, Memoization 197 87.17
0152 Maximum Product Subarray Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 253 88.42
0198 House Robber Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 156 92.24
0213 House Robber II Medium Array, Dynamic_Programming 257 59.62
0509 Fibonacci Number Easy Dynamic_Programming, Math, Recursion, Memoization 139 82.72
0070 Climbing Stairs Easy Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Memoization 127 97.06
0064 Minimum Path Sum Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Matrix 222 95.70
0300 Longest Increasing Subsequence Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Binary_Search 318 82.28
1143 Longest Common Subsequence Medium Top_100_Liked_Questions, String, Dynamic_Programming 307 38.36
0072 Edit Distance Hard Top_100_Liked_Questions, String, Dynamic_Programming 320 63.53
0044 Wildcard Matching Hard Top_Interview_Questions, String, Dynamic_Programming, Greedy, Recursion 401 86.11
0010 Regular Expression Matching Hard Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Recursion 292 58.58

Udemy Backtracking/Recursion
0022 Generate Parentheses Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Backtracking 210 78.51
0039 Combination Sum Medium Top_100_Liked_Questions, Array, Backtracking 317 86.85
0216 Combination Sum III Medium Array, Backtracking 175 90.91
0078 Subsets Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Bit_Manipulation, Backtracking 191 97.44
0017 Letter Combinations of a Phone Number Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Backtracking 262 73.59
0046 Permutations Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Backtracking 186 100.00

Udemy Bit Manipulation
0191 Number of 1 Bits Easy Top_Interview_Questions, Bit_Manipulation 237 68.44
0389 Find the Difference Easy String, Hash_Table, Sorting, Bit_Manipulation 256 64.81
0190 Reverse Bits Easy Top_Interview_Questions, Bit_Manipulation, Divide_and_Conquer 198 81.82
0461 Hamming Distance Easy Bit_Manipulation 150 96.15
0338 Counting Bits Easy Top_100_Liked_Questions, Dynamic_Programming, Bit_Manipulation 186 99.26
0371 Sum of Two Integers Medium Top_Interview_Questions, Math, Bit_Manipulation 129 95.45
0029 Divide Two Integers Medium Top_Interview_Questions, Math, Bit_Manipulation 281 31.67

Udemy Design
0155 Min Stack Easy Top_100_Liked_Questions, Top_Interview_Questions, Stack, Design 331 84.88

Data Structure I

Day 1 Array
0217 Contains Duplicate Easy Top_Interview_Questions, Array, Hash_Table, Sorting 719 73.49
0053 Maximum Subarray Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Divide_and_Conquer 662 82.48

Day 2 Array
0001 Two Sum Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table 234 92.75
0088 Merge Sorted Array Easy Top_Interview_Questions, Array, Sorting, Two_Pointers 311 33.40

Day 3 Array
0350 Intersection of Two Arrays II Easy Top_Interview_Questions, Array, Hash_Table, Sorting, Binary_Search, Two_Pointers 321 73.37
0121 Best Time to Buy and Sell Stock Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 609 94.06

Day 4 Array
0566 Reshape the Matrix Easy Array, Matrix, Simulation 239 99.05
0118 Pascal's Triangle Easy Top_Interview_Questions, Array, Dynamic_Programming 277 33.22

Day 5 Array
0036 Valid Sudoku Medium Top_Interview_Questions, Array, Hash_Table, Matrix 346 65.03
0074 Search a 2D Matrix Medium Top_100_Liked_Questions, Array, Binary_Search, Matrix 290 40.17

Day 6 String
0387 First Unique Character in a String Easy Top_Interview_Questions, String, Hash_Table, Counting, Queue 369 82.68
0383 Ransom Note Easy String, Hash_Table, Counting 333 79.58
0242 Valid Anagram Easy Top_Interview_Questions, String, Hash_Table, Sorting 251 87.65

Day 7 Linked List
0141 Linked List Cycle Easy Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Two_Pointers, Linked_List 223 91.85
0021 Merge Two Sorted Lists Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion 176 96.25
0203 Remove Linked List Elements Easy Linked_List, Recursion 233 91.22

Day 8 Linked List
0206 Reverse Linked List Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion 279 45.78
0083 Remove Duplicates from Sorted List Easy Linked_List 274 77.82

Day 9 Stack Queue
0020 Valid Parentheses Easy Top_100_Liked_Questions, Top_Interview_Questions, String, Stack 226 72.53
0232 Implement Queue using Stacks Easy Stack, Design, Queue 258 70.86

Day 10 Tree
0144 Binary Tree Preorder Traversal Easy Depth_First_Search, Tree, Binary_Tree, Stack 277 37.90
0094 Binary Tree Inorder Traversal Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Stack 269 38.80
0145 Binary Tree Postorder Traversal Easy Depth_First_Search, Tree, Binary_Tree, Stack 211 80.00

Day 11 Tree
0102 Binary Tree Level Order Traversal Medium Top_100_Liked_Questions, Top_Interview_Questions, Breadth_First_Search, Tree, Binary_Tree 332 67.53
0104 Maximum Depth of Binary Tree Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 236 83.39
0101 Symmetric Tree Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 190 91.36

Day 12 Tree
0226 Invert Binary Tree Easy Top_100_Liked_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 233 54.90
0112 Path Sum Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 322 36.41

Day 13 Tree
0700 Search in a Binary Search Tree Easy Tree, Binary_Tree, Binary_Search_Tree 251 88.31
0701 Insert into a Binary Search Tree Medium Tree, Binary_Tree, Binary_Search_Tree 311 79.03

Day 14 Tree
0098 Validate Binary Search Tree Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 330 41.38
0653 Two Sum IV - Input is a BST Easy Hash_Table, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Two_Pointers, Binary_Search_Tree 231 96.08
0235 Lowest Common Ancestor of a Binary Search Tree Easy Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 404 75.59

Data Structure II

Day 1 Array
0136 Single Number Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Bit_Manipulation 344 83.63
0169 Majority Element Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Sorting, Counting, Divide_and_Conquer 460 51.25
0015 3Sum Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Two_Pointers 761 90.55

Day 2 Array
0075 Sort Colors Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Two_Pointers 198 85.66
0056 Merge Intervals Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting 320 94.22
0706 Design HashMap Easy Array, Hash_Table, Design, Linked_List, Hash_Function 405 92.11

Day 3 Array
0119 Pascal's Triangle II Easy Array, Dynamic_Programming 157 97.27
0048 Rotate Image Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Math, Matrix 287 46.50
0059 Spiral Matrix II Medium Array, Matrix, Simulation 153 100.00

Day 4 Array
0240 Search a 2D Matrix II Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search, Matrix, Divide_and_Conquer 460 66.08
0435 Non-overlapping Intervals Medium Array, Dynamic_Programming, Sorting, Greedy 1040 85.07

Day 5 Array
0334 Increasing Triplet Subsequence Medium Top_Interview_Questions, Array, Greedy 672 60.61
0238 Product of Array Except Self Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Prefix_Sum 669 48.96
0560 Subarray Sum Equals K Medium Top_100_Liked_Questions, Array, Hash_Table, Prefix_Sum 692 53.27

Day 6 String
0415 Add Strings Easy String, Math, Simulation 296 76.00
0409 Longest Palindrome Easy String, Hash_Table, Greedy 259 60.71

Day 7 String
0290 Word Pattern Easy String, Hash_Table 177 89.55
0763 Partition Labels Medium Top_100_Liked_Questions, String, Hash_Table, Greedy, Two_Pointers 235 84.75

Day 8 String
0049 Group Anagrams Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, String, Hash_Table, Sorting 506 86.55
0043 Multiply Strings Medium String, Math, Simulation 390 56.25

Day 9 String
0187 Repeated DNA Sequences Medium String, Hash_Table, Bit_Manipulation, Sliding_Window, Hash_Function, Rolling_Hash 319 79.03
0005 Longest Palindromic Substring Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming 323 75.48

Day 10 Linked List
0002 Add Two Numbers Medium Top_100_Liked_Questions, Top_Interview_Questions, Math, Linked_List, Recursion 417 50.44
0142 Linked List Cycle II Medium Top_100_Liked_Questions, Hash_Table, Two_Pointers, Linked_List 192 63.39

Day 11 Linked List
0160 Intersection of Two Linked Lists Easy Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Two_Pointers, Linked_List 262 83.50
0082 Remove Duplicates from Sorted List II Medium Two_Pointers, Linked_List 241 91.04

Day 12 Linked List
0024 Swap Nodes in Pairs Medium Top_100_Liked_Questions, Linked_List, Recursion 149 99.39
0707 Design Linked List Medium Design, Linked_List 243 100.00

Day 13 Linked List
0025 Reverse Nodes in k-Group Hard Top_100_Liked_Questions, Linked_List, Recursion 194 87.72
0143 Reorder List Medium Two_Pointers, Stack, Linked_List, Recursion 395 82.26

Day 14 Stack Queue
0155 Min Stack Easy Top_100_Liked_Questions, Top_Interview_Questions, Stack, Design 331 84.88

Day 15 Tree
0108 Convert Sorted Array to Binary Search Tree Easy Top_Interview_Questions, Array, Tree, Binary_Tree, Binary_Search_Tree, Divide_and_Conquer 334 35.39
0105 Construct Binary Tree from Preorder and Inorder Traversal Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Tree, Binary_Tree, Divide_and_Conquer 370 58.31
0103 Binary Tree Zigzag Level Order Traversal Medium Top_Interview_Questions, Breadth_First_Search, Tree, Binary_Tree 316 34.25

Day 16 Tree
0199 Binary Tree Right Side View Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 194 92.89
0113 Path Sum II Medium Depth_First_Search, Tree, Binary_Tree, Backtracking 364 78.67
0450 Delete Node in a BST Medium Tree, Binary_Tree, Binary_Search_Tree 257 84.62

Day 17 Tree
0230 Kth Smallest Element in a BST Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 393 33.33
0173 Binary Search Tree Iterator Medium Tree, Binary_Tree, Stack, Design, Binary_Search_Tree, Iterator 563 46.91

Day 18 Tree
0236 Lowest Common Ancestor of a Binary Tree Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree 386 45.21
0297 Serialize and Deserialize Binary Tree Hard Top_Interview_Questions, String, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Design 475 78.85

Day 19 Graph
0841 Keys and Rooms Medium Depth_First_Search, Breadth_First_Search, Graph 189 69.23

Day 20 Heap Priority Queue
0215 Kth Largest Element in an Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Heap_Priority_Queue, Divide_and_Conquer, Quickselect 839 34.43
0347 Top K Frequent Elements Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Sorting, Heap_Priority_Queue, Counting, Divide_and_Conquer, Quickselect, Bucket_Sort 268 99.74

Day 21 Heap Priority Queue
0451 Sort Characters By Frequency Medium String, Hash_Table, Sorting, Heap_Priority_Queue, Counting, Bucket_Sort 288 81.72

Algorithm I

Day 1 Binary Search
0704 Binary Search Easy Array, Binary_Search 261 77.91
0278 First Bad Version Easy Binary_Search, Interactive 349 76.86
0035 Search Insert Position Easy Top_100_Liked_Questions, Array, Binary_Search 267 50.32

Day 2 Two Pointers
0189 Rotate Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Math, Two_Pointers 483 86.95

Day 3 Two Pointers
0283 Move Zeroes Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Two_Pointers 516 79.07
0167 Two Sum II - Input Array Is Sorted Medium Array, Binary_Search, Two_Pointers 403 68.74

Day 4 Two Pointers
0344 Reverse String Easy Top_Interview_Questions, String, Two_Pointers, Recursion 445 69.75
0557 Reverse Words in a String III Easy String, Two_Pointers 215 98.10

Day 5 Two Pointers
0876 Middle of the Linked List Easy Two_Pointers, Linked_List 136 76.52
0019 Remove Nth Node From End of List Medium Top_100_Liked_Questions, Top_Interview_Questions, Two_Pointers, Linked_List 180 91.58

Day 6 Sliding Window
0003 Longest Substring Without Repeating Characters Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Sliding_Window 258 91.09
0567 Permutation in String Medium String, Hash_Table, Two_Pointers, Sliding_Window 169 100.00

Day 7 Breadth First Search Depth First Search
0733 Flood Fill Easy Array, Depth_First_Search, Breadth_First_Search, Matrix 230 97.76
0695 Max Area of Island Medium Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find 324 24.06

Day 8 Breadth First Search Depth First Search
0617 Merge Two Binary Trees Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 243 72.83
0116 Populating Next Right Pointers in Each Node Medium Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Linked_List 355 69.02

Day 9 Breadth First Search Depth First Search
0542 01 Matrix Medium Array, Dynamic_Programming, Breadth_First_Search, Matrix 441 94.06
0994 Rotting Oranges Medium Array, Breadth_First_Search, Matrix 308 57.93

Day 10 Recursion Backtracking
0021 Merge Two Sorted Lists Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion 176 96.25
0206 Reverse Linked List Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion 279 45.78

Day 11 Recursion Backtracking
0077 Combinations Medium Backtracking 244 100.00
0046 Permutations Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Backtracking 186 100.00
0784 Letter Case Permutation Medium String, Bit_Manipulation, Backtracking 219 84.62

Day 12 Dynamic Programming
0070 Climbing Stairs Easy Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Memoization 127 97.06
0198 House Robber Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 156 92.24
0120 Triangle Medium Array, Dynamic_Programming 194 97.87

Day 13 Bit Manipulation
0231 Power of Two Easy Math, Bit_Manipulation, Recursion 161 86.81
0191 Number of 1 Bits Easy Top_Interview_Questions, Bit_Manipulation 237 68.44

Day 14 Bit Manipulation
0190 Reverse Bits Easy Top_Interview_Questions, Bit_Manipulation, Divide_and_Conquer 198 81.82
0136 Single Number Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Bit_Manipulation 344 83.63

Algorithm II

Day 1 Binary Search
0034 Find First and Last Position of Element in Sorted Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search 228 83.38
0033 Search in Rotated Sorted Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search 184 86.08
0074 Search a 2D Matrix Medium Top_100_Liked_Questions, Array, Binary_Search, Matrix 290 40.17

Day 2 Binary Search
0153 Find Minimum in Rotated Sorted Array Medium Top_100_Liked_Questions, Array, Binary_Search 262 60.96
0162 Find Peak Element Medium Top_Interview_Questions, Array, Binary_Search 297 53.85

Day 3 Two Pointers
0082 Remove Duplicates from Sorted List II Medium Two_Pointers, Linked_List 241 91.04
0015 3Sum Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Two_Pointers 761 90.55

Day 4 Two Pointers
0844 Backspace String Compare Easy String, Two_Pointers, Stack, Simulation 126 98.31
0011 Container With Most Water Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Greedy, Two_Pointers 474 89.18

Day 5 Sliding Window
0438 Find All Anagrams in a String Medium Top_100_Liked_Questions, String, Hash_Table, Sliding_Window 561 54.68
0713 Subarray Product Less Than K Medium Array, Sliding_Window 336 92.11
0209 Minimum Size Subarray Sum Medium Array, Binary_Search, Prefix_Sum, Sliding_Window 315 96.73

Day 6 Breadth First Search Depth First Search
0200 Number of Islands Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find 252 95.41
0547 Number of Provinces Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find 229 79.73

Day 7 Breadth First Search Depth First Search
0117 Populating Next Right Pointers in Each Node II Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Linked_List 199 94.67
0572 Subtree of Another Tree Easy Depth_First_Search, Tree, Binary_Tree, Hash_Function, String_Matching 214 92.39

Day 8 Breadth First Search Depth First Search
0130 Surrounded Regions Medium Top_Interview_Questions, Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find 355 84.42
0797 All Paths From Source to Target Medium Depth_First_Search, Breadth_First_Search, Graph, Backtracking 232 100.00

Day 9 Recursion Backtracking
0078 Subsets Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Bit_Manipulation, Backtracking 191 97.44
0090 Subsets II Medium Array, Bit_Manipulation, Backtracking 366 58.09

Day 10 Recursion Backtracking
0047 Permutations II Medium Array, Backtracking 406 76.36
0039 Combination Sum Medium Top_100_Liked_Questions, Array, Backtracking 317 86.85
0040 Combination Sum II Medium Array, Backtracking 348 80.92

Day 11 Recursion Backtracking
0017 Letter Combinations of a Phone Number Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Backtracking 262 73.59
0022 Generate Parentheses Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Backtracking 210 78.51
0079 Word Search Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Matrix, Backtracking 463 68.49

Day 12 Dynamic Programming
0213 House Robber II Medium Array, Dynamic_Programming 257 59.62
0055 Jump Game Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Greedy 670 66.67

Day 13 Dynamic Programming
0045 Jump Game II Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Greedy 227 98.14
0062 Unique Paths Medium Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Combinatorics 209 49.18

Day 14 Dynamic Programming
0005 Longest Palindromic Substring Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming 323 75.48
0413 Arithmetic Slices Medium Array, Dynamic_Programming 156 100.00

Day 15 Dynamic Programming
0091 Decode Ways Medium Top_Interview_Questions, String, Dynamic_Programming 237 76.88
0139 Word Break Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Dynamic_Programming, Trie, Memoization 197 87.17

Day 16 Dynamic Programming
0300 Longest Increasing Subsequence Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Binary_Search 318 82.28
0673 Number of Longest Increasing Subsequence Medium Array, Dynamic_Programming, Segment_Tree, Binary_Indexed_Tree 226 91.67

Day 17 Dynamic Programming
1143 Longest Common Subsequence Medium Top_100_Liked_Questions, String, Dynamic_Programming 307 38.36
0583 Delete Operation for Two Strings Medium String, Dynamic_Programming 197 100.00

Day 18 Dynamic Programming
0072 Edit Distance Hard Top_100_Liked_Questions, String, Dynamic_Programming 320 63.53
0322 Coin Change Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Breadth_First_Search 332 50.68
0343 Integer Break Medium Dynamic_Programming, Math 218 63.89

Day 19 Bit Manipulation
0201 Bitwise AND of Numbers Range Medium Bit_Manipulation 368 80.00

Day 20 Others
0384 Shuffle an Array Medium Top_Interview_Questions, Array, Math, Randomized 940 72.09

Day 21 Others
0202 Happy Number Easy Top_Interview_Questions, Hash_Table, Math, Two_Pointers 261 45.08
0149 Max Points on a Line Hard Top_Interview_Questions, Array, Hash_Table, Math, Geometry 307 83.33

Binary Search I

Day 1
0704 Binary Search Easy Array, Binary_Search 261 77.91
0374 Guess Number Higher or Lower Easy Binary_Search, Interactive 134 94.19

Day 2
0035 Search Insert Position Easy Top_100_Liked_Questions, Array, Binary_Search 267 50.32
0852 Peak Index in a Mountain Array Easy Array, Binary_Search 433 94.29

Day 3
0367 Valid Perfect Square Easy Math, Binary_Search 137 94.55

Day 4
0069 Sqrt(x) Easy Top_Interview_Questions, Math, Binary_Search 153 95.75
0744 Find Smallest Letter Greater Than Target Easy Array, Binary_Search 162 100.00

Day 5
0278 First Bad Version Easy Binary_Search, Interactive 349 76.86
0034 Find First and Last Position of Element in Sorted Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search 228 83.38

Day 6
0441 Arranging Coins Easy Math, Binary_Search 150 84.21

Day 7
0167 Two Sum II - Input Array Is Sorted Medium Array, Binary_Search, Two_Pointers 403 68.74

Day 8
0074 Search a 2D Matrix Medium Top_100_Liked_Questions, Array, Binary_Search, Matrix 290 40.17

Day 9

Day 10
0350 Intersection of Two Arrays II Easy Top_Interview_Questions, Array, Hash_Table, Sorting, Binary_Search, Two_Pointers 321 73.37
0633 Sum of Square Numbers Medium Math, Binary_Search, Two_Pointers 126 100.00

Day 11
0033 Search in Rotated Sorted Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search 184 86.08

Day 12
0153 Find Minimum in Rotated Sorted Array Medium Top_100_Liked_Questions, Array, Binary_Search 262 60.96

Binary Search II

Day 1
0209 Minimum Size Subarray Sum Medium Array, Binary_Search, Prefix_Sum, Sliding_Window 315 96.73
0611 Valid Triangle Number Medium Array, Sorting, Greedy, Binary_Search, Two_Pointers 203 100.00

Day 2
0658 Find K Closest Elements Medium Array, Sorting, Binary_Search, Two_Pointers, Heap_Priority_Queue 375 95.16

Day 3
0300 Longest Increasing Subsequence Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Binary_Search 318 82.28

Day 4
0875 Koko Eating Bananas Medium Array, Binary_Search 267 93.85

Day 5
0287 Find the Duplicate Number Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search, Two_Pointers, Bit_Manipulation 656 66.21

Day 6

Day 7

Day 8
0240 Search a 2D Matrix II Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search, Matrix, Divide_and_Conquer 460 66.08
0275 H-Index II Medium Array, Binary_Search 398 81.82

Day 9
0540 Single Element in a Sorted Array Medium Array, Binary_Search 274 86.67

Day 10
0222 Count Complete Tree Nodes

Day 11
0826 Most Profit Assigning Work Medium Array, Sorting, Greedy, Binary_Search, Two_Pointers 366 100.00
0436 Find Right Interval Medium Array, Sorting, Binary_Search 333 100.00

Day 12
0081 Search in Rotated Sorted Array II Medium Array, Binary_Search 352 42.31
0162 Find Peak Element Medium Top_Interview_Questions, Array, Binary_Search 297 53.85

Day 13
0154 Find Minimum in Rotated Sorted Array II Hard Array, Binary_Search 275 84.00
0528 Random Pick with Weight Medium Math, Binary_Search, Prefix_Sum, Randomized 393 91.38

Day 14

Day 15

Day 16

Day 17

Day 18

Day 19

Day 20
0911 Online Election Medium Array, Hash_Table, Binary_Search, Design 766 83.33

Dynamic Programming I

Day 1
0509 Fibonacci Number Easy Dynamic_Programming, Math, Recursion, Memoization 139 82.72

Day 2
0070 Climbing Stairs Easy Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Memoization 127 97.06
0746 Min Cost Climbing Stairs Easy Array, Dynamic_Programming 171 96.76

Day 3
0198 House Robber Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 156 92.24
0213 House Robber II Medium Array, Dynamic_Programming 257 59.62
0740 Delete and Earn Medium Array, Hash_Table, Dynamic_Programming 192 100.00

Day 4
0055 Jump Game Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Greedy 670 66.67
0045 Jump Game II Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Greedy 227 98.14

Day 5
0053 Maximum Subarray Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Divide_and_Conquer 662 82.48

Day 6
0152 Maximum Product Subarray Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 253 88.42

Day 7
0121 Best Time to Buy and Sell Stock Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming 609 94.06
0122 Best Time to Buy and Sell Stock II Medium Top_Interview_Questions, Array, Dynamic_Programming, Greedy 197 95.10

Day 8
0309 Best Time to Buy and Sell Stock with Cooldown Medium Array, Dynamic_Programming 272 73.33
0714 Best Time to Buy and Sell Stock with Transaction Fee Medium Array, Dynamic_Programming, Greedy 417 90.91

Day 9
0139 Word Break Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Dynamic_Programming, Trie, Memoization 197 87.17
0042 Trapping Rain Water Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Two_Pointers, Stack, Monotonic_Stack 196 100.00

Day 10
0413 Arithmetic Slices Medium Array, Dynamic_Programming 156 100.00
0091 Decode Ways Medium Top_Interview_Questions, String, Dynamic_Programming 237 76.88

Day 11
0264 Ugly Number II Medium Hash_Table, Dynamic_Programming, Math, Heap_Priority_Queue 182 95.45
0096 Unique Binary Search Trees Medium Top_100_Liked_Questions, Dynamic_Programming, Math, Tree, Binary_Tree, Binary_Search_Tree 147 88.52

Day 12
0118 Pascal's Triangle Easy Top_Interview_Questions, Array, Dynamic_Programming 277 33.22
0119 Pascal's Triangle II Easy Array, Dynamic_Programming 157 97.27

Day 13
0120 Triangle Medium Array, Dynamic_Programming 194 97.87

Day 14
0304 Range Sum Query 2D - Immutable Medium Array, Matrix, Design, Prefix_Sum 1373 85.71

Day 15
0062 Unique Paths Medium Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Combinatorics 209 49.18
0063 Unique Paths II Medium Array, Dynamic_Programming, Matrix 187 84.62

Day 16
0064 Minimum Path Sum Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Matrix 222 95.70
0221 Maximal Square Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Matrix 614 44.00

Day 17
0005 Longest Palindromic Substring Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming 323 75.48
0516 Longest Palindromic Subsequence Medium String, Dynamic_Programming 243 87.50

Day 18
0300 Longest Increasing Subsequence Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Binary_Search 318 82.28
0376 Wiggle Subsequence Medium Array, Dynamic_Programming, Greedy 162 88.89

Day 19
0392 Is Subsequence Easy String, Dynamic_Programming, Two_Pointers 156 87.74
1143 Longest Common Subsequence Medium Top_100_Liked_Questions, String, Dynamic_Programming 307 38.36
0072 Edit Distance Hard Top_100_Liked_Questions, String, Dynamic_Programming 320 63.53

Day 20
0322 Coin Change Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Breadth_First_Search 332 50.68
0518 Coin Change II Medium Array, Dynamic_Programming 139 100.00

Day 21
0377 Combination Sum IV Medium Array, Dynamic_Programming 217 72.41
0343 Integer Break Medium Dynamic_Programming, Math 218 63.89
0279 Perfect Squares Medium Top_Interview_Questions, Dynamic_Programming, Math, Breadth_First_Search 176 98.80

Programming Skills I

Day 1 Basic Data Type

Day 2 Operator
0191 Number of 1 Bits Easy Top_Interview_Questions, Bit_Manipulation 237 68.44

Day 3 Conditional Statements

Day 4 Loop
0202 Happy Number Easy Top_Interview_Questions, Hash_Table, Math, Two_Pointers 261 45.08

Day 5 Function
0589 N-ary Tree Preorder Traversal Easy Depth_First_Search, Tree, Stack 233 84.02
0496 Next Greater Element I Easy Array, Hash_Table, Stack, Monotonic_Stack 171 100.00

Day 6 Array
0283 Move Zeroes Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Two_Pointers 516 79.07

Day 7 Array
0566 Reshape the Matrix Easy Array, Matrix, Simulation 239 99.05

Day 8 String
0389 Find the Difference Easy String, Hash_Table, Sorting, Bit_Manipulation 256 64.81

Day 9 String
0709 To Lower Case Easy String 142 98.68

Day 10 Linked List and Tree
0876 Middle of the Linked List Easy Two_Pointers, Linked_List 136 76.52
0104 Maximum Depth of Binary Tree Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 236 83.39
0404 Sum of Left Leaves Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 173 86.05

Day 11 Containers and Libraries
0232 Implement Queue using Stacks Easy Stack, Design, Queue 258 70.86
0242 Valid Anagram Easy Top_Interview_Questions, String, Hash_Table, Sorting 251 87.65
0217 Contains Duplicate Easy Top_Interview_Questions, Array, Hash_Table, Sorting 719 73.49

Day 12 Class and Object
0303 Range Sum Query - Immutable Easy Array, Design, Prefix_Sum 472 63.64

Programming Skills II

Day 1
0896 Monotonic Array Easy Array 576 90.91
0028 Find the Index of the First Occurrence in a String Easy Top_Interview_Questions, String, Two_Pointers, String_Matching 257 32.35

Day 2
0110 Balanced Binary Tree Easy Depth_First_Search, Tree, Binary_Tree 310 63.63
0459 Repeated Substring Pattern Easy String, String_Matching 201 100.00

Day 3
0150 Evaluate Reverse Polish Notation Medium Top_Interview_Questions, Array, Math, Stack 233 88.82
0066 Plus One Easy Top_Interview_Questions, Array, Math 303 35.18

Day 4
0043 Multiply Strings Medium String, Math, Simulation 390 56.25

Day 5
0067 Add Binary Easy String, Math, Bit_Manipulation, Simulation 327 32.67

Day 6
0739 Daily Temperatures Medium Top_100_Liked_Questions, Array, Stack, Monotonic_Stack 936 80.54
0058 Length of Last Word Easy String 243 63.33

Day 7
0048 Rotate Image Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Math, Matrix 287 46.50

Day 8
0054 Spiral Matrix Medium Top_Interview_Questions, Array, Matrix, Simulation 224 62.50

Day 9
0429 N-ary Tree Level Order Traversal Medium Breadth_First_Search, Tree 248 75.86

Day 10
0503 Next Greater Element II Medium Array, Stack, Monotonic_Stack 331 92.68
0556 Next Greater Element III Medium String, Math, Two_Pointers 137 80.00

Day 11
0049 Group Anagrams Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, String, Hash_Table, Sorting 506 86.55

Day 12
0438 Find All Anagrams in a String Medium Top_100_Liked_Questions, String, Hash_Table, Sliding_Window 561 54.68
0713 Subarray Product Less Than K Medium Array, Sliding_Window 336 92.11

Day 13
0304 Range Sum Query 2D - Immutable Medium Array, Matrix, Design, Prefix_Sum 1373 85.71
0910 Smallest Range II Medium Array, Math, Sorting, Greedy 234 100.00

Day 14
0143 Reorder List Medium Two_Pointers, Stack, Linked_List, Recursion 395 82.26
0138 Copy List with Random Pointer Medium Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Linked_List 274 80.58

Day 15
0002 Add Two Numbers Medium Top_100_Liked_Questions, Top_Interview_Questions, Math, Linked_List, Recursion 417 50.44
0445 Add Two Numbers II Medium Math, Stack, Linked_List 240 82.61

Day 16
0061 Rotate List Medium Two_Pointers, Linked_List 193 92.16
0173 Binary Search Tree Iterator Medium Tree, Binary_Tree, Stack, Design, Binary_Search_Tree, Iterator 563 46.91

Day 17
0860 Lemonade Change Easy Array, Greedy 413 86.96

Day 18
0155 Min Stack Easy Top_100_Liked_Questions, Top_Interview_Questions, Stack, Design 331 84.88
0341 Flatten Nested List Iterator Medium Top_Interview_Questions, Depth_First_Search, Tree, Stack, Design, Queue, Iterator 210 100.00

Day 19
0707 Design Linked List Medium Design, Linked_List 243 100.00

Day 20
0380 Insert Delete GetRandom O(1) Medium Top_Interview_Questions, Array, Hash_Table, Math, Design, Randomized 1326 68.23
0622 Design Circular Queue Medium Array, Design, Linked_List, Queue 234 92.68
0729 My Calendar I Medium Binary_Search, Design, Ordered_Set, Segment_Tree 378 69.70

Graph Theory I

Day 1 Matrix Related Problems
0733 Flood Fill Easy Array, Depth_First_Search, Breadth_First_Search, Matrix 230 97.76
0200 Number of Islands Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find 252 95.41

Day 2 Matrix Related Problems
0695 Max Area of Island Medium Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find 324 24.06

Day 3 Matrix Related Problems

Day 4 Matrix Related Problems
0417 Pacific Atlantic Water Flow Medium Array, Depth_First_Search, Breadth_First_Search, Matrix 319 100.00

Day 5 Matrix Related Problems
0542 01 Matrix Medium Array, Dynamic_Programming, Breadth_First_Search, Matrix 441 94.06

Day 6 Matrix Related Problems

Day 7 Standard Traversal
0797 All Paths From Source to Target Medium Depth_First_Search, Breadth_First_Search, Graph, Backtracking 232 100.00
0841 Keys and Rooms Medium Depth_First_Search, Breadth_First_Search, Graph 189 69.23

Day 8 Standard Traversal
0547 Number of Provinces Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find 229 79.73

Day 9 Standard Traversal
0802 Find Eventual Safe States Medium Depth_First_Search, Breadth_First_Search, Graph, Topological_Sort 511 100.00

Day 10 Standard Traversal
0847 Shortest Path Visiting All Nodes Hard Dynamic_Programming, Breadth_First_Search, Bit_Manipulation, Graph, Bitmask 164 100.00

Day 11 Breadth First Search
0365 Water and Jug Problem Medium Math, Depth_First_Search, Breadth_First_Search 130 100.00

Day 12 Breadth First Search
0433 Minimum Genetic Mutation Medium String, Hash_Table, Breadth_First_Search 204 82.08
0752 Open the Lock Medium Array, String, Hash_Table, Breadth_First_Search 310 100.00
0127 Word Ladder Hard Top_Interview_Questions, String, Hash_Table, Breadth_First_Search 396 98.68

Day 13 Graph Theory

Day 14 Graph Theory
0886 Possible Bipartition Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find 397 100.00
0785 Is Graph Bipartite? Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find 215 82.35

Algorithms

# Title Difficulty Tag Time, ms Time, %
1143 Longest Common Subsequence Medium Top_100_Liked_Questions, String, Dynamic_Programming, Algorithm_II_Day_17_Dynamic_Programming, Dynamic_Programming_I_Day_19, Udemy_Dynamic_Programming 307 38.36
0994 Rotting Oranges Medium Array, Breadth_First_Search, Matrix, Algorithm_I_Day_9_Breadth_First_Search_Depth_First_Search, Level_2_Day_10_Graph/BFS/DFS 308 57.93
0911 Online Election Medium Array, Hash_Table, Binary_Search, Design, Binary_Search_II_Day_20 766 83.33
0910 Smallest Range II Medium Array, Math, Sorting, Greedy, Programming_Skills_II_Day_13 234 100.00
0909 Snakes and Ladders Medium Array, Breadth_First_Search, Matrix 203 100.00
0908 Smallest Range I Easy Array, Math 202 87.50
0907 Sum of Subarray Minimums Medium Array, Dynamic_Programming, Stack, Monotonic_Stack 341 100.00
0906 Super Palindromes Hard Math, Enumeration 153 100.00
0905 Sort Array By Parity Easy Array, Sorting, Two_Pointers 219 75.00
0904 Fruit Into Baskets Medium Array, Hash_Table, Sliding_Window 371 100.00
0903 Valid Permutations for DI Sequence Hard Dynamic_Programming 140 100.00
0902 Numbers At Most N Given Digit Set Hard Array, Dynamic_Programming, Math, Binary_Search 138 100.00
0901 Online Stock Span Medium Stack, Design, Monotonic_Stack, Data_Stream 641 75.00
0900 RLE Iterator Medium Array, Design, Counting, Iterator 175 83.33
0899 Orderly Queue Hard String, Math, Sorting 148 100.00
0898 Bitwise ORs of Subarrays Medium Array, Dynamic_Programming, Bit_Manipulation 812 100.00
0897 Increasing Order Search Tree Easy Depth_First_Search, Tree, Binary_Tree, Stack, Binary_Search_Tree 128 85.71
0896 Monotonic Array Easy Array, Programming_Skills_II_Day_1 576 90.91
0895 Maximum Frequency Stack Hard Hash_Table, Stack, Design, Ordered_Set 617 100.00
0894 All Possible Full Binary Trees Medium Dynamic_Programming, Tree, Binary_Tree, Recursion, Memoization 257 100.00
0893 Groups of Special-Equivalent Strings Medium Array, String, Hash_Table 141 100.00
0892 Surface Area of 3D Shapes Easy Array, Math, Matrix, Geometry 180 100.00
0891 Sum of Subsequence Widths Hard Array, Math, Sorting 481 100.00
0890 Find and Replace Pattern Medium Array, String, Hash_Table 150 100.00
0889 Construct Binary Tree from Preorder and Postorder Traversal Medium Array, Hash_Table, Tree, Binary_Tree, Divide_and_Conquer 168 100.00
0888 Fair Candy Swap Easy Array, Hash_Table, Sorting, Binary_Search 318 100.00
0887 Super Egg Drop Hard Dynamic_Programming, Math, Binary_Search 119 100.00
0886 Possible Bipartition Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find, Graph_Theory_I_Day_14_Graph_Theory 397 100.00
0885 Spiral Matrix III Medium Array, Matrix, Simulation 265 100.00
0884 Uncommon Words from Two Sentences Easy String, Hash_Table 171 100.00
0883 Projection Area of 3D Shapes Easy Array, Math, Matrix, Geometry 173 100.00
0882 Reachable Nodes In Subdivided Graph Hard Heap_Priority_Queue, Graph, Shortest_Path 434 100.00
0881 Boats to Save People Medium Array, Sorting, Greedy, Two_Pointers 370 96.07
0880 Decoded String at Index Medium String, Stack 134 100.00
0879 Profitable Schemes Hard Array, Dynamic_Programming 198 75.00
0878 Nth Magical Number Hard Math, Binary_Search 124 100.00
0877 Stone Game Medium Array, Dynamic_Programming, Math, Game_Theory 136 88.24
0876 Middle of the Linked List Easy Two_Pointers, Linked_List, Algorithm_I_Day_5_Two_Pointers, Programming_Skills_I_Day_10_Linked_List_and_Tree, Level_1_Day_4_Linked_List, Udemy_Linked_List 136 76.52
0875 Koko Eating Bananas Medium Array, Binary_Search, Binary_Search_II_Day_4 267 93.85
0874 Walking Robot Simulation Medium Array, Simulation 274 100.00
0873 Length of Longest Fibonacci Subsequence Medium Array, Hash_Table, Dynamic_Programming 341 90.00
0872 Leaf-Similar Trees Easy Depth_First_Search, Tree, Binary_Tree 140 100.00
0871 Minimum Number of Refueling Stops Hard Array, Dynamic_Programming, Greedy, Heap_Priority_Queue 203 92.86
0870 Advantage Shuffle Medium Array, Sorting, Greedy 698 100.00
0869 Reordered Power of 2 Medium Math, Sorting, Counting, Enumeration 145 87.50
0868 Binary Gap Easy Bit_Manipulation 142 100.00
0867 Transpose Matrix Easy Array, Matrix, Simulation 201 100.00
0866 Prime Palindrome Medium Math 143 100.00
0865 Smallest Subtree with all the Deepest Nodes Medium Hash_Table, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 147 100.00
0864 Shortest Path to Get All Keys Hard Breadth_First_Search, Bit_Manipulation 176 100.00
0863 All Nodes Distance K in Binary Tree Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 147 95.83
0862 Shortest Subarray with Sum at Least K Hard Array, Binary_Search, Heap_Priority_Queue, Prefix_Sum, Sliding_Window, Queue, Monotonic_Queue 563 84.62
0861 Score After Flipping Matrix Medium Array, Greedy, Matrix, Bit_Manipulation 135 71.43
0860 Lemonade Change Easy Array, Greedy, Programming_Skills_II_Day_17 413 86.96
0859 Buddy Strings Easy String, Hash_Table 149 91.01
0858 Mirror Reflection Medium Math, Geometry 120 100.00
0857 Minimum Cost to Hire K Workers Hard Array, Sorting, Greedy, Heap_Priority_Queue 302 100.00
0856 Score of Parentheses Medium String, Stack 129 84.62
0855 Exam Room Medium Design, Ordered_Set 644 83.33
0854 K-Similar Strings Hard String, Breadth_First_Search 136 100.00
0853 Car Fleet Medium Array, Sorting, Stack, Monotonic_Stack 757 85.29
0852 Peak Index in a Mountain Array Easy Array, Binary_Search, Binary_Search_I_Day_2 433 94.29
0851 Loud and Rich Medium Array, Depth_First_Search, Graph, Topological_Sort 347 100.00
0850 Rectangle Area II Hard Array, Ordered_Set, Segment_Tree, Line_Sweep 171 100.00
0849 Maximize Distance to Closest Person Medium Array 196 88.46
0848 Shifting Letters Medium Array, String 537 93.75
0847 Shortest Path Visiting All Nodes Hard Dynamic_Programming, Breadth_First_Search, Bit_Manipulation, Graph, Bitmask, Graph_Theory_I_Day_10_Standard_Traversal 164 100.00
0846 Hand of Straights Medium Array, Hash_Table, Sorting, Greedy 306 96.15
0845 Longest Mountain in Array Medium Array, Dynamic_Programming, Two_Pointers, Enumeration 222 100.00
0844 Backspace String Compare Easy String, Two_Pointers, Stack, Simulation, Algorithm_II_Day_4_Two_Pointers, Level_1_Day_14_Stack 126 98.31
0843 Guess the Word Hard Array, String, Math, Game_Theory, Interactive 75 100.00
0842 Split Array into Fibonacci Sequence Medium String, Backtracking 142 100.00
0841 Keys and Rooms Medium Depth_First_Search, Breadth_First_Search, Graph, Data_Structure_II_Day_19_Graph, Graph_Theory_I_Day_7_Standard_Traversal 189 69.23
0840 Magic Squares In Grid Medium Array, Math, Matrix 149 100.00
0839 Similar String Groups Hard Array, String, Depth_First_Search, Breadth_First_Search, Union_Find 205 100.00
0838 Push Dominoes Medium String, Dynamic_Programming, Two_Pointers 270 100.00
0837 New 21 Game Medium Dynamic_Programming, Math, Sliding_Window, Probability_and_Statistics 144 75.00
0836 Rectangle Overlap Easy Math, Geometry 121 100.00
0835 Image Overlap Medium Array, Matrix 163 100.00
0834 Sum of Distances in Tree Hard Dynamic_Programming, Depth_First_Search, Tree, Graph 746 100.00
0833 Find And Replace in String Medium Array, String, Sorting 158 100.00
0832 Flipping an Image Easy Array, Matrix, Two_Pointers, Simulation 190 94.44
0831 Masking Personal Information Medium String 149 100.00
0830 Positions of Large Groups Easy String 221 100.00
0829 Consecutive Numbers Sum Hard Math, Enumeration 151 100.00
0828 Count Unique Characters of All Substrings of a Given String Hard String, Hash_Table, Dynamic_Programming 216 100.00
0827 Making A Large Island Hard Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find 985 100.00
0826 Most Profit Assigning Work Medium Array, Sorting, Greedy, Binary_Search, Two_Pointers, Binary_Search_II_Day_11 366 100.00
0825 Friends Of Appropriate Ages Medium Array, Sorting, Binary_Search, Two_Pointers 278 100.00
0824 Goat Latin Easy String 146 100.00
0823 Binary Trees With Factors Medium Array, Hash_Table, Dynamic_Programming 298 100.00
0822 Card Flipping Game Medium Array, Hash_Table 186 100.00
0821 Shortest Distance to a Character Easy Array, String, Two_Pointers 168 88.00
0820 Short Encoding of Words Medium Array, String, Hash_Table, Trie 231 100.00
0819 Most Common Word Easy String, Hash_Table, Counting 211 83.33
0818 Race Car Hard Dynamic_Programming 123 100.00
0817 Linked List Components Medium Hash_Table, Linked_List 239 100.00
0816 Ambiguous Coordinates Medium String, Backtracking 231 100.00
0815 Bus Routes Hard Array, Hash_Table, Breadth_First_Search, Level_2_Day_11_Graph/BFS/DFS 429 100.00
0814 Binary Tree Pruning Medium Depth_First_Search, Tree, Binary_Tree 127 100.00
0813 Largest Sum of Averages Medium Array, Dynamic_Programming 160 100.00
0812 Largest Triangle Area Easy Array, Math, Geometry 156 71.43
0811 Subdomain Visit Count Medium Array, String, Hash_Table, Counting 220 100.00
0810 Chalkboard XOR Game Hard Array, Math, Bit_Manipulation, Game_Theory, Brainteaser 172 100.00
0809 Expressive Words Medium Array, String, Two_Pointers 158 100.00
0808 Soup Servings Medium Dynamic_Programming, Math, Probability_and_Statistics 112 100.00
0807 Max Increase to Keep City Skyline Medium Array, Greedy, Matrix 158 100.00
0806 Number of Lines To Write String Easy Array, String 134 100.00
0805 Split Array With Same Average Hard Array, Dynamic_Programming, Math, Bit_Manipulation, Bitmask 142 100.00
0804 Unique Morse Code Words Easy Array, String, Hash_Table 158 80.00
0803 Bricks Falling When Hit Hard Array, Matrix, Union_Find 742 100.00
0802 Find Eventual Safe States Medium Depth_First_Search, Breadth_First_Search, Graph, Topological_Sort, Graph_Theory_I_Day_9_Standard_Traversal 511 100.00
0801 Minimum Swaps To Make Sequences Increasing Hard Array, Dynamic_Programming 617 83.33
0799 Champagne Tower Medium Dynamic_Programming 153 100.00
0798 Smallest Rotation with Highest Score Hard Array, Prefix_Sum 470 100.00
0797 All Paths From Source to Target Medium Depth_First_Search, Breadth_First_Search, Graph, Backtracking, Algorithm_II_Day_8_Breadth_First_Search_Depth_First_Search, Graph_Theory_I_Day_7_Standard_Traversal 232 100.00
0796 Rotate String Easy String, String_Matching 134 100.00
0795 Number of Subarrays with Bounded Maximum Medium Array, Two_Pointers 361 66.67
0794 Valid Tic-Tac-Toe State Medium Array, String 138 100.00
0793 Preimage Size of Factorial Zeroes Function Hard Math, Binary_Search 114 100.00
0792 Number of Matching Subsequences Medium String, Hash_Table, Sorting, Trie 346 100.00
0791 Custom Sort String Medium String, Hash_Table, Sorting 133 90.00
0790 Domino and Tromino Tiling Medium Dynamic_Programming 116 100.00
0789 Escape The Ghosts Medium Array, Math 187 100.00
0788 Rotated Digits Medium Dynamic_Programming, Math 137 80.00
0787 Cheapest Flights Within K Stops Medium Dynamic_Programming, Depth_First_Search, Breadth_First_Search, Heap_Priority_Queue, Graph, Shortest_Path 185 99.20
0786 K-th Smallest Prime Fraction Medium Array, Binary_Search, Heap_Priority_Queue 165 100.00
0785 Is Graph Bipartite? Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find, Graph_Theory_I_Day_14_Graph_Theory 215 82.35
0784 Letter Case Permutation Medium String, Bit_Manipulation, Backtracking, Algorithm_I_Day_11_Recursion_Backtracking 219 84.62
0783 Minimum Distance Between BST Nodes Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 144 96.35
0782 Transform to Chessboard Hard Array, Math, Matrix, Bit_Manipulation 188 100.00
0781 Rabbits in Forest Medium Array, Hash_Table, Math, Greedy 132 100.00
0780 Reaching Points Hard Math 139 100.00
0779 K-th Symbol in Grammar Medium Math, Bit_Manipulation, Recursion 114 100.00
0778 Swim in Rising Water Hard Array, Depth_First_Search, Breadth_First_Search, Binary_Search, Matrix, Heap_Priority_Queue, Union_Find 190 100.00
0777 Swap Adjacent in LR String Medium String, Two_Pointers 188 100.00
0775 Global and Local Inversions Medium Array, Math 495 100.00
0773 Sliding Puzzle Hard Array, Breadth_First_Search, Matrix 166 100.00
0771 Jewels and Stones Easy String, Hash_Table 143 99.08
0770 Basic Calculator IV Hard String, Hash_Table, Math, Stack, Recursion 222 100.00
0769 Max Chunks To Make Sorted Medium Array, Sorting, Greedy, Stack, Monotonic_Stack 136 90.00
0768 Max Chunks To Make Sorted II Hard Array, Sorting, Greedy, Stack, Monotonic_Stack 202 100.00
0767 Reorganize String Medium String, Hash_Table, Sorting, Greedy, Heap_Priority_Queue, Counting 148 100.00
0766 Toeplitz Matrix Easy Array, Matrix 174 100.00
0765 Couples Holding Hands Hard Depth_First_Search, Greedy, Breadth_First_Search, Graph, Union_Find 131 100.00
0764 Largest Plus Sign Medium Array, Dynamic_Programming 415 100.00
0763 Partition Labels Medium Top_100_Liked_Questions, String, Hash_Table, Greedy, Two_Pointers, Data_Structure_II_Day_7_String 235 84.75
0762 Prime Number of Set Bits in Binary Representation Easy Math, Bit_Manipulation 147 100.00
0761 Special Binary String Hard String, Recursion 128 100.00
0757 Set Intersection Size At Least Two Hard Array, Sorting, Greedy 298 100.00
0756 Pyramid Transition Matrix Medium Depth_First_Search, Breadth_First_Search, Bit_Manipulation 268 100.00
0754 Reach a Number Medium Math, Binary_Search 134 100.00
0753 Cracking the Safe Hard Depth_First_Search, Graph, Eulerian_Circuit 147 100.00
0752 Open the Lock Medium Array, String, Hash_Table, Breadth_First_Search, Graph_Theory_I_Day_12_Breadth_First_Search 310 100.00
0749 Contain Virus Hard Array, Depth_First_Search, Breadth_First_Search, Matrix, Simulation 201 100.00
0748 Shortest Completing Word Easy Array, String, Hash_Table 172 100.00
0747 Largest Number At Least Twice of Others Easy Array, Sorting 147 98.21
0746 Min Cost Climbing Stairs Easy Array, Dynamic_Programming, Dynamic_Programming_I_Day_2, Level_1_Day_11_Dynamic_Programming 171 96.76
0745 Prefix and Suffix Search Hard String, Design, Trie, Udemy_Trie_and_Heap 1638 100.00
0744 Find Smallest Letter Greater Than Target Easy Array, Binary_Search, Binary_Search_I_Day_4 162 100.00
0743 Network Delay Time Medium Depth_First_Search, Breadth_First_Search, Heap_Priority_Queue, Graph, Shortest_Path 321 98.55
0741 Cherry Pickup Hard Array, Dynamic_Programming, Matrix 196 100.00
0740 Delete and Earn Medium Array, Hash_Table, Dynamic_Programming, Dynamic_Programming_I_Day_3 192 100.00
0739 Daily Temperatures Medium Top_100_Liked_Questions, Array, Stack, Monotonic_Stack, Programming_Skills_II_Day_6 936 80.54
0738 Monotone Increasing Digits Medium Math, Greedy 127 100.00
0736 Parse Lisp Expression Hard String, Hash_Table, Stack, Recursion 172 100.00
0735 Asteroid Collision Medium Array, Stack, Level_2_Day_18_Stack 243 100.00
0733 Flood Fill Easy Array, Depth_First_Search, Breadth_First_Search, Matrix, Algorithm_I_Day_7_Breadth_First_Search_Depth_First_Search, Graph_Theory_I_Day_1_Matrix_Related_Problems, Level_1_Day_9_Graph/BFS/DFS 230 97.76
0732 My Calendar III Hard Binary_Search, Design, Ordered_Set, Segment_Tree 294 100.00
0731 My Calendar II Medium Binary_Search, Design, Ordered_Set, Segment_Tree 371 100.00
0730 Count Different Palindromic Subsequences Hard String, Dynamic_Programming 233 100.00
0729 My Calendar I Medium Binary_Search, Design, Ordered_Set, Segment_Tree, Programming_Skills_II_Day_20 378 69.70
0728 Self Dividing Numbers Easy Math 142 100.00
0726 Number of Atoms Hard String, Hash_Table, Sorting, Stack 149 100.00
0725 Split Linked List in Parts Medium Linked_List 162 95.00
0724 Find Pivot Index Easy Array, Prefix_Sum, Level_1_Day_1_Prefix_Sum 255 88.92
0722 Remove Comments Medium Array, String 164 100.00
0721 Accounts Merge Medium Array, String, Depth_First_Search, Breadth_First_Search, Union_Find 364 100.00
0720 Longest Word in Dictionary Medium Array, String, Hash_Table, Sorting, Trie 209 100.00
0719 Find K-th Smallest Pair Distance Hard Array, Sorting, Binary_Search, Two_Pointers 172 100.00
0718 Maximum Length of Repeated Subarray Medium Array, Dynamic_Programming, Binary_Search, Sliding_Window, Hash_Function, Rolling_Hash 270 91.43
0717 1-bit and 2-bit Characters Easy Array 165 100.00
0715 Range Module Hard Design, Ordered_Set, Segment_Tree 638 58.33
0714 Best Time to Buy and Sell Stock with Transaction Fee Medium Array, Dynamic_Programming, Greedy, Dynamic_Programming_I_Day_8 417 90.91
0713 Subarray Product Less Than K Medium Array, Sliding_Window, Algorithm_II_Day_5_Sliding_Window, Programming_Skills_II_Day_12, Udemy_Arrays 336 92.11
0712 Minimum ASCII Delete Sum for Two Strings Medium String, Dynamic_Programming 176 100.00
0710 Random Pick with Blacklist Hard Hash_Table, Math, Sorting, Binary_Search, Randomized 632 100.00
0709 To Lower Case Easy String, Programming_Skills_I_Day_9_String 142 98.68
0707 Design Linked List Medium Design, Linked_List, Data_Structure_II_Day_12_Linked_List, Programming_Skills_II_Day_19, Udemy_Linked_List 243 100.00
0706 Design HashMap Easy Array, Hash_Table, Design, Linked_List, Hash_Function, Data_Structure_II_Day_2_Array 405 92.11
0705 Design HashSet Easy Array, Hash_Table, Design, Linked_List, Hash_Function 385 75.61
0704 Binary Search Easy Array, Binary_Search, Algorithm_I_Day_1_Binary_Search, Binary_Search_I_Day_1, Level_1_Day_7_Binary_Search, Udemy_Binary_Search 261 77.91
0703 Kth Largest Element in a Stream Easy Tree, Binary_Tree, Design, Heap_Priority_Queue, Binary_Search_Tree, Data_Stream 286 95.45
0701 Insert into a Binary Search Tree Medium Tree, Binary_Tree, Binary_Search_Tree, Data_Structure_I_Day_13_Tree, Udemy_Tree_Stack_Queue 311 79.03
0700 Search in a Binary Search Tree Easy Tree, Binary_Tree, Binary_Search_Tree, Data_Structure_I_Day_13_Tree 251 88.31
0699 Falling Squares Hard Array, Ordered_Set, Segment_Tree 293 100.00
0698 Partition to K Equal Sum Subsets Medium Array, Dynamic_Programming, Bit_Manipulation, Backtracking, Bitmask, Memoization 191 100.00
0697 Degree of an Array Easy Array, Hash_Table, Udemy_Arrays 289 84.62
0696 Count Binary Substrings Easy String, Two_Pointers 222 100.00
0695 Max Area of Island Medium Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find, Algorithm_I_Day_7_Breadth_First_Search_Depth_First_Search, Graph_Theory_I_Day_2_Matrix_Related_Problems 324 24.06
0693 Binary Number with Alternating Bits Easy Bit_Manipulation 129 100.00
0692 Top K Frequent Words Medium String, Hash_Table, Sorting, Heap_Priority_Queue, Counting, Trie, Bucket_Sort, Level_1_Day_15_Heap 239 81.10
0691 Stickers to Spell Word Hard Array, String, Dynamic_Programming, Bit_Manipulation, Backtracking, Bitmask 249 100.00
0690 Employee Importance Medium Hash_Table, Depth_First_Search, Breadth_First_Search 255 100.00
0689 Maximum Sum of 3 Non-Overlapping Subarrays Hard Array, Dynamic_Programming 248 100.00
0688 Knight Probability in Chessboard Medium Dynamic_Programming 144 100.00
0687 Longest Univalue Path Medium Depth_First_Search, Tree, Binary_Tree 303 100.00
0686 Repeated String Match Medium String, String_Matching 164 100.00
0685 Redundant Connection II Hard Depth_First_Search, Breadth_First_Search, Graph, Union_Find 176 100.00
0684 Redundant Connection Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find 181 88.24
0682 Baseball Game Easy Array, Stack, Simulation 159 100.00
0680 Valid Palindrome II Easy String, Greedy, Two_Pointers 296 79.17
0679 24 Game Hard Array, Math, Backtracking 175 100.00
0678 Valid Parenthesis String Medium String, Dynamic_Programming, Greedy, Stack 133 100.00
0677 Map Sum Pairs Medium String, Hash_Table, Design, Trie 197 80.00
0676 Implement Magic Dictionary Medium String, Hash_Table, Design, Trie 256 100.00
0675 Cut Off Trees for Golf Event Hard Array, Breadth_First_Search, Matrix, Heap_Priority_Queue 777 100.00
0674 Longest Continuous Increasing Subsequence Easy Array 201 84.21
0673 Number of Longest Increasing Subsequence Medium Array, Dynamic_Programming, Segment_Tree, Binary_Indexed_Tree, Algorithm_II_Day_16_Dynamic_Programming 226 91.67
0672 Bulb Switcher II Medium Math, Depth_First_Search, Breadth_First_Search, Bit_Manipulation 131 100.00
0671 Second Minimum Node In a Binary Tree Easy Depth_First_Search, Tree, Binary_Tree 128 100.00
0670 Maximum Swap Medium Math, Greedy 143 100.00
0669 Trim a Binary Search Tree Medium Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 195 100.00
0668 Kth Smallest Number in Multiplication Table Hard Math, Binary_Search 151 100.00
0667 Beautiful Arrangement II Medium Array, Math 175 100.00
0665 Non-decreasing Array Medium Array 256 85.71
0664 Strange Printer Hard String, Dynamic_Programming 196 100.00
0662 Maximum Width of Binary Tree Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 189 75.00
0661 Image Smoother Easy Array, Matrix 352 100.00
0659 Split Array into Consecutive Subsequences Medium Array, Hash_Table, Greedy, Heap_Priority_Queue 352 100.00
0658 Find K Closest Elements Medium Array, Sorting, Binary_Search, Two_Pointers, Heap_Priority_Queue, Binary_Search_II_Day_2 375 95.16
0657 Robot Return to Origin Easy String, Simulation 186 100.00
0655 Print Binary Tree Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 176 100.00
0654 Maximum Binary Tree Medium Array, Tree, Binary_Tree, Stack, Monotonic_Stack, Divide_and_Conquer 271 90.00
0653 Two Sum IV - Input is a BST Easy Hash_Table, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Two_Pointers, Binary_Search_Tree, Data_Structure_I_Day_14_Tree 231 96.08
0652 Find Duplicate Subtrees Medium Hash_Table, Depth_First_Search, Tree, Binary_Tree 266 76.00
0650 2 Keys Keyboard Medium Dynamic_Programming, Math 115 100.00
0649 Dota2 Senate Medium String, Greedy, Queue 217 100.00
0648 Replace Words Medium Array, String, Hash_Table, Trie 392 100.00
0647 Palindromic Substrings Medium Top_100_Liked_Questions, String, Dynamic_Programming 266 67.83
0646 Maximum Length of Pair Chain Medium Array, Dynamic_Programming, Sorting, Greedy 249 100.00
0645 Set Mismatch Easy Array, Hash_Table, Sorting, Bit_Manipulation 246 88.46
0643 Maximum Average Subarray I Easy Array, Sliding_Window 494 98.65
0641 Design Circular Deque Medium Array, Design, Linked_List, Queue 232 100.00
0640 Solve the Equation Medium String, Math, Simulation 170 66.67
0639 Decode Ways II Hard String, Dynamic_Programming 259 100.00
0638 Shopping Offers Medium Array, Dynamic_Programming, Bit_Manipulation, Backtracking, Bitmask, Memoization 195 100.00
0637 Average of Levels in Binary Tree Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 249 100.00
0636 Exclusive Time of Functions Medium Array, Stack 270 80.00
0633 Sum of Square Numbers Medium Math, Binary_Search, Two_Pointers, Binary_Search_I_Day_10 126 100.00
0632 Smallest Range Covering Elements from K Lists Hard Array, Hash_Table, Sorting, Greedy, Heap_Priority_Queue, Sliding_Window 399 83.33
0630 Course Schedule III Hard Array, Greedy, Heap_Priority_Queue 536 100.00
0629 K Inverse Pairs Array Hard Dynamic_Programming 155 100.00
0628 Maximum Product of Three Numbers Easy Array, Math, Sorting 276 97.30
0627 Swap Salary Easy Database, SQL_I_Day_2_Select_and_Order 400 51.04
0626 Exchange Seats Medium Database 502 50.56
0623 Add One Row to Tree Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 202 100.00
0622 Design Circular Queue Medium Array, Design, Linked_List, Queue, Programming_Skills_II_Day_20 234 92.68
0621 Task Scheduler Medium Array, Hash_Table, Sorting, Greedy, Heap_Priority_Queue, Counting, Level_2_Day_5_Greedy 266 98.36
0620 Not Boring Movies Easy Database 305 59.80
0617 Merge Two Binary Trees Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Algorithm_I_Day_8_Breadth_First_Search_Depth_First_Search 243 72.83
0611 Valid Triangle Number Medium Array, Sorting, Greedy, Binary_Search, Two_Pointers, Binary_Search_II_Day_1 203 100.00
0609 Find Duplicate File in System Medium Array, String, Hash_Table 426 100.00
0608 Tree Node Medium LeetCode_Curated_SQL_70, Database, SQL_I_Day_4_Union_and_Select 794 48.38
0607 Sales Person Easy LeetCode_Curated_SQL_70, Database, SQL_I_Day_6_Union 2142 44.56
0606 Construct String from Binary Tree Easy String, Depth_First_Search, Tree, Binary_Tree 187 100.00
0605 Can Place Flowers Easy Array, Greedy, Udemy_Arrays 209 85.71
0601 Human Traffic of Stadium Hard Database 529 51.80
0600 Non-negative Integers without Consecutive Ones Hard Dynamic_Programming 142 100.00
0599 Minimum Index Sum of Two Lists Easy Array, String, Hash_Table 293 100.00
0598 Range Addition II Easy Array, Math 176 66.67
0596 Classes More Than 5 Students Easy Database 484 50.92
0595 Big Countries Easy Database, SQL_I_Day_1_Select 417 56.09
0594 Longest Harmonious Subsequence Easy Array, Hash_Table, Sorting 331 100.00
0593 Valid Square Medium Math, Geometry 161 83.33
0592 Fraction Addition and Subtraction Medium String, Math, Simulation 164 100.00
0591 Tag Validator Hard String, Stack 177 100.00
0590 N-ary Tree Postorder Traversal Easy Depth_First_Search, Tree, Stack 237 88.10
0589 N-ary Tree Preorder Traversal Easy Depth_First_Search, Tree, Stack, Programming_Skills_I_Day_5_Function, Level_1_Day_6_Tree 233 84.02
0587 Erect the Fence Hard Array, Math, Geometry 470 100.00
0586 Customer Placing the Largest Number of Orders Easy LeetCode_Curated_SQL_70, Database, SQL_I_Day_8_Function 768 44.85
0584 Find Customer Referee Easy Database, SQL_I_Day_1_Select 779 43.48
0583 Delete Operation for Two Strings Medium String, Dynamic_Programming, Algorithm_II_Day_17_Dynamic_Programming 197 100.00
0581 Shortest Unsorted Continuous Subarray Medium Array, Sorting, Greedy, Two_Pointers, Stack, Monotonic_Stack 246 100.00
0576 Out of Boundary Paths Medium Dynamic_Programming 153 100.00
0575 Distribute Candies Easy Array, Hash_Table 538 76.92
0572 Subtree of Another Tree Easy Depth_First_Search, Tree, Binary_Tree, Hash_Function, String_Matching, Algorithm_II_Day_7_Breadth_First_Search_Depth_First_Search 214 92.39
0567 Permutation in String Medium String, Hash_Table, Two_Pointers, Sliding_Window, Algorithm_I_Day_6_Sliding_Window 169 100.00
0566 Reshape the Matrix Easy Array, Matrix, Simulation, Data_Structure_I_Day_4_Array, Programming_Skills_I_Day_7_Array 239 99.05
0565 Array Nesting Medium Array, Depth_First_Search 553 100.00
0564 Find the Closest Palindrome Hard String, Math 179 100.00
0563 Binary Tree Tilt Easy Depth_First_Search, Tree, Binary_Tree 197 100.00
0561 Array Partition Easy Array, Sorting, Greedy, Counting_Sort 337 90.48
0560 Subarray Sum Equals K Medium Top_100_Liked_Questions, Array, Hash_Table, Prefix_Sum, Data_Structure_II_Day_5_Array 692 53.27
0559 Maximum Depth of N-ary Tree Easy Depth_First_Search, Breadth_First_Search, Tree 196 100.00
0558 Logical OR of Two Binary Grids Represented as Quad-Trees Medium Tree, Divide_and_Conquer 268 100.00
0557 Reverse Words in a String III Easy String, Two_Pointers, Algorithm_I_Day_4_Two_Pointers 215 98.10
0556 Next Greater Element III Medium String, Math, Two_Pointers, Programming_Skills_II_Day_10 137 80.00
0554 Brick Wall Medium Array, Hash_Table 307 100.00
0553 Optimal Division Medium Array, Dynamic_Programming, Math 154 100.00
0552 Student Attendance Record II Hard Dynamic_Programming 151 100.00
0551 Student Attendance Record I Easy String 151 95.00
0547 Number of Provinces Medium Depth_First_Search, Breadth_First_Search, Graph, Union_Find, Algorithm_II_Day_6_Breadth_First_Search_Depth_First_Search, Graph_Theory_I_Day_8_Standard_Traversal, Level_2_Day_19_Union_Find 229 79.73
0546 Remove Boxes Hard Array, Dynamic_Programming, Memoization 283 100.00
0543 Diameter of Binary Tree Easy Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree, Level_2_Day_7_Tree, Udemy_Tree_Stack_Queue 307 43.93
0542 01 Matrix Medium Array, Dynamic_Programming, Breadth_First_Search, Matrix, Algorithm_I_Day_9_Breadth_First_Search_Depth_First_Search, Graph_Theory_I_Day_5_Matrix_Related_Problems 441 94.06
0541 Reverse String II Easy String, Two_Pointers 200 83.33
0540 Single Element in a Sorted Array Medium Array, Binary_Search, Binary_Search_II_Day_9 274 86.67
0539 Minimum Time Difference Medium Array, String, Math, Sorting 183 100.00
0538 Convert BST to Greater Tree Medium Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 252 77.78
0537 Complex Number Multiplication Medium String, Math, Simulation 171 75.00
0535 Encode and Decode TinyURL Medium String, Hash_Table, Design, Hash_Function 183 81.25
0532 K-diff Pairs in an Array Medium Array, Hash_Table, Sorting, Binary_Search, Two_Pointers, Udemy_Arrays 230 84.62
0530 Minimum Absolute Difference in BST Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 209 86.96
0529 Minesweeper Medium Array, Depth_First_Search, Breadth_First_Search, Matrix 243 87.50
0528 Random Pick with Weight Medium Math, Binary_Search, Prefix_Sum, Randomized, Binary_Search_II_Day_13 393 91.38
0526 Beautiful Arrangement Medium Array, Dynamic_Programming, Bit_Manipulation, Backtracking, Bitmask 107 100.00
0525 Contiguous Array Medium Array, Hash_Table, Prefix_Sum 471 100.00
0524 Longest Word in Dictionary through Deleting Medium Array, String, Sorting, Two_Pointers 307 100.00
0523 Continuous Subarray Sum Medium Array, Hash_Table, Math, Prefix_Sum 682 95.45
0522 Longest Uncommon Subsequence II Medium Array, String, Hash_Table, Sorting, Two_Pointers 163 100.00
0521 Longest Uncommon Subsequence I Easy String 146 88.89
0520 Detect Capital Easy String 161 84.54
0519 Random Flip Matrix Medium Hash_Table, Math, Randomized, Reservoir_Sampling 270 100.00
0518 Coin Change II Medium Array, Dynamic_Programming, Dynamic_Programming_I_Day_20 139 100.00
0517 Super Washing Machines Hard Array, Greedy 210 100.00
0516 Longest Palindromic Subsequence Medium String, Dynamic_Programming, Dynamic_Programming_I_Day_17 243 87.50
0515 Find Largest Value in Each Tree Row Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 238 73.33
0514 Freedom Trail Hard String, Dynamic_Programming, Depth_First_Search, Breadth_First_Search 182 100.00
0513 Find Bottom Left Tree Value Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree 190 88.24
0511 Game Play Analysis I Easy LeetCode_Curated_SQL_70, Database, SQL_I_Day_8_Function 790 45.04
0509 Fibonacci Number Easy Dynamic_Programming, Math, Recursion, Memoization, Dynamic_Programming_I_Day_1, Level_1_Day_10_Dynamic_Programming, Udemy_Dynamic_Programming 139 82.72
0508 Most Frequent Subtree Sum Medium Hash_Table, Depth_First_Search, Tree, Binary_Tree 246 80.00
0507 Perfect Number Easy Math 172 81.82
0506 Relative Ranks Easy Array, Sorting, Heap_Priority_Queue 244 94.23
0504 Base 7 Easy Math 136 100.00
0503 Next Greater Element II Medium Array, Stack, Monotonic_Stack, Programming_Skills_II_Day_10 331 92.68
0502 IPO Hard Array, Sorting, Greedy, Heap_Priority_Queue 799 54.55
0501 Find Mode in Binary Search Tree Easy Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 235 86.67
0500 Keyboard Row Easy Array, String, Hash_Table 170 85.19
0498 Diagonal Traverse Medium Array, Matrix, Simulation 430 61.54
0497 Random Point in Non-overlapping Rectangles Medium Math, Binary_Search, Prefix_Sum, Ordered_Set, Randomized, Reservoir_Sampling 759 100.00
0496 Next Greater Element I Easy Array, Hash_Table, Stack, Monotonic_Stack, Programming_Skills_I_Day_5_Function 171 100.00
0495 Teemo Attacking Easy Array, Simulation 283 100.00
0494 Target Sum Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Backtracking 308 89.61
0493 Reverse Pairs Hard Array, Binary_Search, Ordered_Set, Divide_and_Conquer, Segment_Tree, Binary_Indexed_Tree, Merge_Sort 887 66.67
0492 Construct the Rectangle Easy Math 202 88.89
0491 Non-decreasing Subsequences Medium Array, Hash_Table, Bit_Manipulation, Backtracking 499 100.00
0488 Zuma Game Hard String, Dynamic_Programming, Breadth_First_Search, Memoization 1727 100.00
0486 Predict the Winner Medium Array, Dynamic_Programming, Math, Recursion, Game_Theory 158 84.62
0485 Max Consecutive Ones Easy Array 272 88.46
0483 Smallest Good Base Hard Math, Binary_Search 164 100.00
0482 License Key Formatting Easy String 234 87.18
0481 Magical String Medium String, Two_Pointers 124 100.00
0480 Sliding Window Median Hard Array, Hash_Table, Heap_Priority_Queue, Sliding_Window 409 100.00
0479 Largest Palindrome Product Hard Math 147 100.00
0478 Generate Random Point in a Circle Medium Math, Geometry, Randomized, Rejection_Sampling 862 100.00
0477 Total Hamming Distance Medium Array, Math, Bit_Manipulation 298 100.00
0476 Number Complement Easy Bit_Manipulation 133 100.00
0475 Heaters Medium Array, Sorting, Binary_Search, Two_Pointers 356 87.50
0474 Ones and Zeroes Medium Array, String, Dynamic_Programming 204 100.00
0473 Matchsticks to Square Medium Array, Dynamic_Programming, Bit_Manipulation, Backtracking, Bitmask 255 100.00
0472 Concatenated Words Hard Array, String, Dynamic_Programming, Depth_First_Search, Trie 484 100.00
0470 Implement Rand10() Using Rand7() Medium Math, Randomized, Probability_and_Statistics, Rejection_Sampling 220 100.00
0468 Validate IP Address Medium String 192 62.50
0467 Unique Substrings in Wraparound String Medium String, Dynamic_Programming 197 100.00
0466 Count The Repetitions Hard String, Dynamic_Programming 147 100.00
0464 Can I Win Medium Dynamic_Programming, Math, Bit_Manipulation, Bitmask, Memoization, Game_Theory 213 100.00
0463 Island Perimeter Easy Array, Depth_First_Search, Breadth_First_Search, Matrix 381 98.04
0462 Minimum Moves to Equal Array Elements II Medium Array, Math, Sorting 210 100.00
0461 Hamming Distance Easy Bit_Manipulation, Udemy_Bit_Manipulation 150 96.15
0460 LFU Cache Hard Hash_Table, Design, Linked_List, Doubly_Linked_List 1143 100.00
0459 Repeated Substring Pattern Easy String, String_Matching, Programming_Skills_II_Day_2 201 100.00
0458 Poor Pigs Hard Dynamic_Programming, Math, Combinatorics 133 80.00
0457 Circular Array Loop Medium Array, Hash_Table, Two_Pointers 143 100.00
0456 132 Pattern Medium Array, Binary_Search, Stack, Ordered_Set, Monotonic_Stack, Udemy_Arrays 434 100.00
0455 Assign Cookies Easy Array, Sorting, Greedy 260 96.67
0454 4Sum II Medium Top_Interview_Questions, Array, Hash_Table 660 85.71
0453 Minimum Moves to Equal Array Elements Medium Array, Math 282 100.00
0452 Minimum Number of Arrows to Burst Balloons Medium Array, Sorting, Greedy 934 100.00
0451 Sort Characters By Frequency Medium String, Hash_Table, Sorting, Heap_Priority_Queue, Counting, Bucket_Sort, Data_Structure_II_Day_21_Heap_Priority_Queue 288 81.72
0450 Delete Node in a BST Medium Tree, Binary_Tree, Binary_Search_Tree, Data_Structure_II_Day_16_Tree 257 84.62
0449 Serialize and Deserialize BST Medium String, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Design, Binary_Search_Tree 233 100.00
0448 Find All Numbers Disappeared in an Array Easy Array, Hash_Table, Udemy_Arrays 394 100.00
0447 Number of Boomerangs Medium Array, Hash_Table, Math 308 100.00
0446 Arithmetic Slices II - Subsequence Hard Array, Dynamic_Programming 312 100.00
0445 Add Two Numbers II Medium Math, Stack, Linked_List, Programming_Skills_II_Day_15, Udemy_Linked_List 240 82.61
0443 String Compression Medium String, Two_Pointers 198 92.68
0442 Find All Duplicates in an Array Medium Array, Hash_Table, Udemy_Arrays 480 73.81
0441 Arranging Coins Easy Math, Binary_Search, Binary_Search_I_Day_6 150 84.21
0440 K-th Smallest in Lexicographical Order Hard Trie 149 100.00
0438 Find All Anagrams in a String Medium Top_100_Liked_Questions, String, Hash_Table, Sliding_Window, Algorithm_II_Day_5_Sliding_Window, Programming_Skills_II_Day_12, Level_1_Day_12_Sliding_Window/Two_Pointer 561 54.68
0437 Path Sum III Medium Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree, Level_2_Day_7_Tree 403 54.12
0436 Find Right Interval Medium Array, Sorting, Binary_Search, Binary_Search_II_Day_11 333 100.00
0435 Non-overlapping Intervals Medium Array, Dynamic_Programming, Sorting, Greedy, Data_Structure_II_Day_4_Array 1040 85.07
0434 Number of Segments in a String Easy String 167 80.00
0433 Minimum Genetic Mutation Medium String, Hash_Table, Breadth_First_Search, Graph_Theory_I_Day_12_Breadth_First_Search 204 82.08
0432 All O`one Data Structure Hard Hash_Table, Design, Linked_List, Doubly_Linked_List 1200 100.00
0430 Flatten a Multilevel Doubly Linked List Medium Depth_First_Search, Linked_List, Doubly_Linked_List 194 97.44
0429 N-ary Tree Level Order Traversal Medium Breadth_First_Search, Tree, Programming_Skills_II_Day_9 248 75.86
0427 Construct Quad Tree Medium Array, Tree, Matrix, Divide_and_Conquer 221 94.74
0424 Longest Repeating Character Replacement Medium String, Hash_Table, Sliding_Window, Level_1_Day_12_Sliding_Window/Two_Pointer 288 84.38
0423 Reconstruct Original Digits from English Medium String, Hash_Table, Math 349 100.00
0421 Maximum XOR of Two Numbers in an Array Medium Array, Hash_Table, Bit_Manipulation, Trie 710 100.00
0420 Strong Password Checker Hard String, Greedy, Heap_Priority_Queue 157 80.00
0419 Battleships in a Board Medium Array, Depth_First_Search, Matrix 273 76.92
0417 Pacific Atlantic Water Flow Medium Array, Depth_First_Search, Breadth_First_Search, Matrix, Graph_Theory_I_Day_4_Matrix_Related_Problems, Level_2_Day_10_Graph/BFS/DFS, Udemy_Graph 319 100.00
0416 Partition Equal Subset Sum Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Level_2_Day_13_Dynamic_Programming 204 98.82
0415 Add Strings Easy String, Math, Simulation, Data_Structure_II_Day_6_String 296 76.00
0414 Third Maximum Number Easy Array, Sorting 317 73.00
0413 Arithmetic Slices Medium Array, Dynamic_Programming, Algorithm_II_Day_14_Dynamic_Programming, Dynamic_Programming_I_Day_10 156 100.00
0412 Fizz Buzz Easy Top_Interview_Questions, String, Math, Simulation, Udemy_Integers 307 71.81
0410 Split Array Largest Sum Hard Array, Dynamic_Programming, Greedy, Binary_Search 165 100.00
0409 Longest Palindrome Easy String, Hash_Table, Greedy, Data_Structure_II_Day_6_String, Level_1_Day_5_Greedy 259 60.71
0407 Trapping Rain Water II Hard Array, Breadth_First_Search, Matrix, Heap_Priority_Queue 500 100.00
0406 Queue Reconstruction by Height Medium Array, Sorting, Greedy, Segment_Tree, Binary_Indexed_Tree 306 100.00
0405 Convert a Number to Hexadecimal Easy Math, Bit_Manipulation 132 100.00
0404 Sum of Left Leaves Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Programming_Skills_I_Day_10_Linked_List_and_Tree 173 86.05
0403 Frog Jump Hard Array, Dynamic_Programming 240 100.00
0402 Remove K Digits Medium String, Greedy, Stack, Monotonic_Stack 375 75.00
0401 Binary Watch Easy Bit_Manipulation, Backtracking 266 71.43
0400 Nth Digit Medium Math, Binary_Search 271 50.00
0399 Evaluate Division Medium Array, Depth_First_Search, Breadth_First_Search, Graph, Union_Find, Shortest_Path 183 91.49
0398 Random Pick Index Medium Hash_Table, Math, Randomized, Reservoir_Sampling 1091 75.00
0397 Integer Replacement Medium Dynamic_Programming, Greedy, Bit_Manipulation, Memoization 145 87.50
0396 Rotate Function Medium Array, Dynamic_Programming, Math 571 87.50
0395 Longest Substring with At Least K Repeating Characters Medium Top_Interview_Questions, String, Hash_Table, Sliding_Window, Divide_and_Conquer 274 66.67
0394 Decode String Medium Top_100_Liked_Questions, String, Stack, Recursion, Level_1_Day_14_Stack, Udemy_Strings 224 64.86
0393 UTF-8 Validation Medium Array, Bit_Manipulation 219 100.00
0392 Is Subsequence Easy String, Dynamic_Programming, Two_Pointers, Dynamic_Programming_I_Day_19, Level_1_Day_2_String, Udemy_Two_Pointers 156 87.74
0391 Perfect Rectangle Hard Array, Line_Sweep 897 100.00
0390 Elimination Game Medium Math, Recursion 319 55.56
0389 Find the Difference Easy String, Hash_Table, Sorting, Bit_Manipulation, Programming_Skills_I_Day_8_String, Udemy_Bit_Manipulation 256 64.81
0388 Longest Absolute File Path Medium String, Depth_First_Search, Stack 150 100.00
0387 First Unique Character in a String Easy Top_Interview_Questions, String, Hash_Table, Counting, Queue, Data_Structure_I_Day_6_String 369 82.68
0386 Lexicographical Numbers Medium Depth_First_Search, Trie 463 83.33
0385 Mini Parser Medium String, Depth_First_Search, Stack 210 100.00
0384 Shuffle an Array Medium Top_Interview_Questions, Array, Math, Randomized, Algorithm_II_Day_20_Others 940 72.09
0383 Ransom Note Easy String, Hash_Table, Counting, Data_Structure_I_Day_6_String 333 79.58
0382 Linked List Random Node Medium Math, Linked_List, Randomized, Reservoir_Sampling 283 100.00
0381 Insert Delete GetRandom O(1) - Duplicates allowed Hard Array, Hash_Table, Math, Design, Randomized 1313 50.00
0380 Insert Delete GetRandom O(1) Medium Top_Interview_Questions, Array, Hash_Table, Math, Design, Randomized, Programming_Skills_II_Day_20 1326 68.23
0378 Kth Smallest Element in a Sorted Matrix Medium Top_Interview_Questions, Array, Sorting, Binary_Search, Matrix, Heap_Priority_Queue 522 59.78
0377 Combination Sum IV Medium Array, Dynamic_Programming, Dynamic_Programming_I_Day_21 217 72.41
0376 Wiggle Subsequence Medium Array, Dynamic_Programming, Greedy, Dynamic_Programming_I_Day_18 162 88.89
0375 Guess Number Higher or Lower II Medium Dynamic_Programming, Math, Game_Theory 235 75.00
0374 Guess Number Higher or Lower Easy Binary_Search, Interactive, Binary_Search_I_Day_1 134 94.19
0373 Find K Pairs with Smallest Sums Medium Array, Heap_Priority_Queue 1809 80.95
0372 Super Pow Medium Math, Divide_and_Conquer 196 100.00
0371 Sum of Two Integers Medium Top_Interview_Questions, Math, Bit_Manipulation, Udemy_Bit_Manipulation 129 95.45
0368 Largest Divisible Subset Medium Array, Dynamic_Programming, Math, Sorting 412 73.33
0367 Valid Perfect Square Easy Math, Binary_Search, Binary_Search_I_Day_3 137 94.55
0365 Water and Jug Problem Medium Math, Depth_First_Search, Breadth_First_Search, Graph_Theory_I_Day_11_Breadth_First_Search 130 100.00
0363 Max Sum of Rectangle No Larger Than K Hard Array, Dynamic_Programming, Binary_Search, Matrix, Ordered_Set 243 100.00
0357 Count Numbers with Unique Digits Medium Dynamic_Programming, Math, Backtracking 104 100.00
0355 Design Twitter Medium Hash_Table, Design, Heap_Priority_Queue, Linked_List 288 68.75
0354 Russian Doll Envelopes Hard Array, Dynamic_Programming, Sorting, Binary_Search 788 100.00
0352 Data Stream as Disjoint Intervals Hard Binary_Search, Design, Ordered_Set 905 75.00
0350 Intersection of Two Arrays II Easy Top_Interview_Questions, Array, Hash_Table, Sorting, Binary_Search, Two_Pointers, Data_Structure_I_Day_3_Array, Binary_Search_I_Day_10 321 73.37
0349 Intersection of Two Arrays Easy Array, Hash_Table, Sorting, Binary_Search, Two_Pointers 346 66.99
0347 Top K Frequent Elements Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Sorting, Heap_Priority_Queue, Counting, Divide_and_Conquer, Quickselect, Bucket_Sort, Data_Structure_II_Day_20_Heap_Priority_Queue 268 99.74
0345 Reverse Vowels of a String Easy String, Two_Pointers 349 80.63
0344 Reverse String Easy Top_Interview_Questions, String, Two_Pointers, Recursion, Algorithm_I_Day_4_Two_Pointers, Udemy_Strings 445 69.75
0343 Integer Break Medium Dynamic_Programming, Math, Algorithm_II_Day_18_Dynamic_Programming, Dynamic_Programming_I_Day_21 218 63.89
0342 Power of Four Easy Math, Bit_Manipulation, Recursion 150 92.11
0341 Flatten Nested List Iterator Medium Top_Interview_Questions, Depth_First_Search, Tree, Stack, Design, Queue, Iterator, Programming_Skills_II_Day_18 210 100.00
0338 Counting Bits Easy Top_100_Liked_Questions, Dynamic_Programming, Bit_Manipulation, Udemy_Bit_Manipulation 186 99.26
0337 House Robber III Medium Dynamic_Programming, Depth_First_Search, Tree, Binary_Tree, Udemy_Tree_Stack_Queue 282 84.62
0336 Palindrome Pairs Hard Array, String, Hash_Table, Trie 2451 67.33
0335 Self Crossing Hard Array, Math, Geometry 477 100.00
0334 Increasing Triplet Subsequence Medium Top_Interview_Questions, Array, Greedy, Data_Structure_II_Day_5_Array 672 60.61
0332 Reconstruct Itinerary Hard Depth_First_Search, Graph, Eulerian_Circuit 240 93.88
0331 Verify Preorder Serialization of a Binary Tree Medium String, Tree, Binary_Tree, Stack 335 70.00
0330 Patching Array Hard Array, Greedy 201 100.00
0329 Longest Increasing Path in a Matrix Hard Top_Interview_Questions, Dynamic_Programming, Depth_First_Search, Breadth_First_Search, Graph, Memoization, Topological_Sort 322 92.65
0328 Odd Even Linked List Medium Top_Interview_Questions, Linked_List, Level_2_Day_4_Linked_List, Udemy_Linked_List 216 86.96
0327 Count of Range Sum Hard Array, Binary_Search, Ordered_Set, Divide_and_Conquer, Segment_Tree, Binary_Indexed_Tree, Merge_Sort 638 100.00
0326 Power of Three Easy Top_Interview_Questions, Math, Recursion 413 76.12
0324 Wiggle Sort II Medium Top_Interview_Questions, Array, Sorting, Divide_and_Conquer, Quickselect 545 57.14
0322 Coin Change Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Breadth_First_Search, Algorithm_II_Day_18_Dynamic_Programming, Dynamic_Programming_I_Day_20, Level_2_Day_12_Dynamic_Programming 332 50.68
0321 Create Maximum Number Hard Greedy, Stack, Monotonic_Stack 209 100.00
0319 Bulb Switcher Medium Math, Brainteaser 214 77.78
0318 Maximum Product of Word Lengths Medium Array, String, Bit_Manipulation 477 100.00
0316 Remove Duplicate Letters Medium String, Greedy, Stack, Monotonic_Stack 291 81.82
0315 Count of Smaller Numbers After Self Hard Top_Interview_Questions, Array, Binary_Search, Ordered_Set, Divide_and_Conquer, Segment_Tree, Binary_Indexed_Tree, Merge_Sort 1282 88.46
0313 Super Ugly Number Medium Array, Dynamic_Programming, Math 330 100.00
0312 Burst Balloons Hard Array, Dynamic_Programming 210 100.00
0310 Minimum Height Trees Medium Depth_First_Search, Breadth_First_Search, Graph, Topological_Sort 521 97.56
0309 Best Time to Buy and Sell Stock with Cooldown Medium Array, Dynamic_Programming, Dynamic_Programming_I_Day_8 272 73.33
0307 Range Sum Query - Mutable Medium Array, Design, Segment_Tree, Binary_Indexed_Tree 1729 78.79
0306 Additive Number Medium String, Backtracking 261 63.16
0304 Range Sum Query 2D - Immutable Medium Array, Matrix, Design, Prefix_Sum, Dynamic_Programming_I_Day_14, Programming_Skills_II_Day_13, Udemy_2D_Arrays/Matrix 1373 85.71
0303 Range Sum Query - Immutable Easy Array, Design, Prefix_Sum, Programming_Skills_I_Day_12_Class_and_Object 472 63.64
0301 Remove Invalid Parentheses Hard String, Breadth_First_Search, Backtracking 312 100.00
0300 Longest Increasing Subsequence Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Binary_Search, Algorithm_II_Day_16_Dynamic_Programming, Binary_Search_II_Day_3, Dynamic_Programming_I_Day_18, Udemy_Dynamic_Programming 318 82.28
0299 Bulls and Cows Medium String, Hash_Table, Counting, Level_1_Day_13_Hashmap 254 84.82
0297 Serialize and Deserialize Binary Tree Hard Top_Interview_Questions, String, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Design, Data_Structure_II_Day_18_Tree, Udemy_Tree_Stack_Queue 475 78.85
0295 Find Median from Data Stream Hard Top_100_Liked_Questions, Top_Interview_Questions, Sorting, Two_Pointers, Design, Heap_Priority_Queue, Data_Stream 2289 33.60
0292 Nim Game Easy Math, Game_Theory, Brainteaser 129 94.29
0290 Word Pattern Easy String, Hash_Table, Data_Structure_II_Day_7_String 177 89.55
0289 Game of Life Medium Top_Interview_Questions, Array, Matrix, Simulation 174 96.97
0287 Find the Duplicate Number Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search, Two_Pointers, Bit_Manipulation, Binary_Search_II_Day_5 656 66.21
0284 Peeking Iterator Medium Array, Design, Iterator 286 62.50
0283 Move Zeroes Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Two_Pointers, Algorithm_I_Day_3_Two_Pointers, Programming_Skills_I_Day_6_Array, Udemy_Arrays 516 79.07
0282 Expression Add Operators Hard String, Math, Backtracking 367 85.71
0279 Perfect Squares Medium Top_Interview_Questions, Dynamic_Programming, Math, Breadth_First_Search, Dynamic_Programming_I_Day_21 176 98.80
0278 First Bad Version Easy Binary_Search, Interactive, Algorithm_I_Day_1_Binary_Search, Binary_Search_I_Day_5, Level_1_Day_7_Binary_Search 349 76.86
0275 H-Index II Medium Array, Binary_Search, Binary_Search_II_Day_8 398 81.82
0274 H-Index Medium Array, Sorting, Counting_Sort 291 45.45
0273 Integer to English Words Hard String, Math, Recursion, Udemy_Strings 273 82.93
0268 Missing Number Easy Top_Interview_Questions, Array, Hash_Table, Math, Sorting, Binary_Search, Bit_Manipulation 380 83.49
0264 Ugly Number II Medium Hash_Table, Dynamic_Programming, Math, Heap_Priority_Queue, Dynamic_Programming_I_Day_11 182 95.45
0263 Ugly Number Easy Math 243 64.10
0262 Trips and Users Hard Database 577 63.97
0260 Single Number III Medium Array, Bit_Manipulation 222 100.00
0258 Add Digits Easy Math, Simulation, Number_Theory 234 71.64
0257 Binary Tree Paths Easy String, Depth_First_Search, Tree, Binary_Tree, Backtracking 320 72.84
0242 Valid Anagram Easy Top_Interview_Questions, String, Hash_Table, Sorting, Data_Structure_I_Day_6_String, Programming_Skills_I_Day_11_Containers_and_Libraries, Udemy_Strings 251 87.65
0241 Different Ways to Add Parentheses Medium String, Dynamic_Programming, Math, Recursion, Memoization 294 73.47
0240 Search a 2D Matrix II Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search, Matrix, Divide_and_Conquer, Data_Structure_II_Day_4_Array, Binary_Search_II_Day_8 460 66.08
0239 Sliding Window Maximum Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Heap_Priority_Queue, Sliding_Window, Queue, Monotonic_Queue, Udemy_Arrays 1059 86.14
0238 Product of Array Except Self Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Prefix_Sum, Data_Structure_II_Day_5_Array, Udemy_Arrays 669 48.96
0237 Delete Node in a Linked List Easy Top_Interview_Questions, Linked_List 183 93.00
0236 Lowest Common Ancestor of a Binary Tree Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Data_Structure_II_Day_18_Tree, Udemy_Tree_Stack_Queue 386 45.21
0235 Lowest Common Ancestor of a Binary Search Tree Easy Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree, Data_Structure_I_Day_14_Tree, Level_1_Day_8_Binary_Search_Tree 404 75.59
0234 Palindrome Linked List Easy Top_100_Liked_Questions, Top_Interview_Questions, Two_Pointers, Stack, Linked_List, Recursion, Level_2_Day_3_Linked_List, Udemy_Linked_List 641 79.53
0233 Number of Digit One Hard Dynamic_Programming, Math, Recursion 129 100.00
0232 Implement Queue using Stacks Easy Stack, Design, Queue, Data_Structure_I_Day_9_Stack_Queue, Programming_Skills_I_Day_11_Containers_and_Libraries, Level_2_Day_16_Design 258 70.86
0231 Power of Two Easy Math, Bit_Manipulation, Recursion, Algorithm_I_Day_13_Bit_Manipulation 161 86.81
0230 Kth Smallest Element in a BST Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree, Data_Structure_II_Day_17_Tree, Level_2_Day_9_Binary_Search_Tree 393 33.33
0229 Majority Element II Medium Array, Hash_Table, Sorting, Counting 408 71.21
0228 Summary Ranges Easy Array 169 91.89
0227 Basic Calculator II Medium Top_Interview_Questions, String, Math, Stack, Level_2_Day_18_Stack 383 62.50
0226 Invert Binary Tree Easy Top_100_Liked_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Data_Structure_I_Day_12_Tree, Level_2_Day_6_Tree, Udemy_Tree_Stack_Queue 233 54.90
0225 Implement Stack using Queues Easy Stack, Design, Queue 248 73.44
0224 Basic Calculator Hard String, Math, Stack, Recursion 294 93.33
0223 Rectangle Area Medium Math, Geometry 291 66.67
0222 Count Complete Tree Nodes
0221 Maximal Square Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Matrix, Dynamic_Programming_I_Day_16 614 44.00
0220 Contains Duplicate III Medium Array, Sorting, Sliding_Window, Ordered_Set, Bucket_Sort 921 72.22
0219 Contains Duplicate II Easy Array, Hash_Table, Sliding_Window 813 80.46
0218 The Skyline Problem Hard Top_Interview_Questions, Array, Heap_Priority_Queue, Ordered_Set, Divide_and_Conquer, Segment_Tree, Binary_Indexed_Tree, Line_Sweep 365 93.14
0217 Contains Duplicate Easy Top_Interview_Questions, Array, Hash_Table, Sorting, Data_Structure_I_Day_1_Array, Programming_Skills_I_Day_11_Containers_and_Libraries, Udemy_Arrays 719 73.49
0216 Combination Sum III Medium Array, Backtracking, Udemy_Backtracking/Recursion 175 90.91
0215 Kth Largest Element in an Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Heap_Priority_Queue, Divide_and_Conquer, Quickselect, Data_Structure_II_Day_20_Heap_Priority_Queue 839 34.43
0214 Shortest Palindrome Hard String, Hash_Function, String_Matching, Rolling_Hash 278 100.00
0213 House Robber II Medium Array, Dynamic_Programming, Algorithm_II_Day_12_Dynamic_Programming, Dynamic_Programming_I_Day_3, Udemy_Dynamic_Programming 257 59.62
0212 Word Search II Hard Top_Interview_Questions, Array, String, Matrix, Backtracking, Trie 268 100.00
0211 Design Add and Search Words Data Structure Medium String, Depth_First_Search, Design, Trie 2256 87.04
0210 Course Schedule II Medium Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Graph, Topological_Sort, Level_2_Day_11_Graph/BFS/DFS 266 96.32
0209 Minimum Size Subarray Sum Medium Array, Binary_Search, Prefix_Sum, Sliding_Window, Algorithm_II_Day_5_Sliding_Window, Binary_Search_II_Day_1 315 96.73
0208 Implement Trie (Prefix Tree) Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Design, Trie, Level_2_Day_16_Design, Udemy_Trie_and_Heap 689 61.00
0207 Course Schedule Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Graph, Topological_Sort 416 40.10
0206 Reverse Linked List Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion, Data_Structure_I_Day_8_Linked_List, Algorithm_I_Day_10_Recursion_Backtracking, Level_1_Day_3_Linked_List, Udemy_Linked_List 279 45.78
0205 Isomorphic Strings Easy String, Hash_Table, Level_1_Day_2_String 278 79.96
0204 Count Primes Medium Top_Interview_Questions, Array, Math, Enumeration, Number_Theory 360 96.61
0203 Remove Linked List Elements Easy Linked_List, Recursion, Data_Structure_I_Day_7_Linked_List 233 91.22
0202 Happy Number Easy Top_Interview_Questions, Hash_Table, Math, Two_Pointers, Algorithm_II_Day_21_Others, Programming_Skills_I_Day_4_Loop, Level_2_Day_1_Implementation/Simulation 261 45.08
0201 Bitwise AND of Numbers Range Medium Bit_Manipulation, Algorithm_II_Day_19_Bit_Manipulation 368 80.00
0200 Number of Islands Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find, Algorithm_II_Day_6_Breadth_First_Search_Depth_First_Search, Graph_Theory_I_Day_1_Matrix_Related_Problems, Level_1_Day_9_Graph/BFS/DFS, Udemy_Graph 252 95.41
0199 Binary Tree Right Side View Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Data_Structure_II_Day_16_Tree, Level_2_Day_15_Tree 194 92.89
0198 House Robber Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Algorithm_I_Day_12_Dynamic_Programming, Dynamic_Programming_I_Day_3, Level_2_Day_12_Dynamic_Programming, Udemy_Dynamic_Programming 156 92.24
0197 Rising Temperature Easy Database, SQL_I_Day_6_Union 394 94.15
0196 Delete Duplicate Emails Easy Database, SQL_I_Day_2_Select_and_Order 593 94.17
0195 Tenth Line Easy Shell 36 87.50
0194 Transpose File Medium Shell 461 33.47
0193 Valid Phone Numbers Easy Shell 98 88.64
0192 Word Frequency Medium Shell 96 80.40
0191 Number of 1 Bits Easy Top_Interview_Questions, Bit_Manipulation, Algorithm_I_Day_13_Bit_Manipulation, Programming_Skills_I_Day_2_Operator, Udemy_Bit_Manipulation 237 68.44
0190 Reverse Bits Easy Top_Interview_Questions, Bit_Manipulation, Divide_and_Conquer, Algorithm_I_Day_14_Bit_Manipulation, Udemy_Bit_Manipulation 198 81.82
0189 Rotate Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Math, Two_Pointers, Algorithm_I_Day_2_Two_Pointers, Udemy_Arrays 483 86.95
0188 Best Time to Buy and Sell Stock IV Hard Array, Dynamic_Programming 293 68.31
0187 Repeated DNA Sequences Medium String, Hash_Table, Bit_Manipulation, Sliding_Window, Hash_Function, Rolling_Hash, Data_Structure_II_Day_9_String, Udemy_Strings 319 79.03
0185 Department Top Three Salaries Hard Database 757 87.06
0184 Department Highest Salary Medium Database 637 76.01
0183 Customers Who Never Order Easy Database, SQL_I_Day_1_Select 712 33.67
0182 Duplicate Emails Easy Database, SQL_I_Day_10_Where 396 68.40
0181 Employees Earning More Than Their Managers Easy Database 351 94.75
0180 Consecutive Numbers Medium Database 695 38.05
0179 Largest Number Medium Top_Interview_Questions, String, Sorting, Greedy 187 100.00
0178 Rank Scores Medium Database 292 85.14
0177 Nth Highest Salary Medium Database 338 86.68
0176 Second Highest Salary Medium Database, SQL_I_Day_4_Union_and_Select 219 92.54
0175 Combine Two Tables Easy Database, SQL_I_Day_5_Union 473 54.97
0174 Dungeon Game Hard Array, Dynamic_Programming, Matrix 300 66.67
0173 Binary Search Tree Iterator Medium Tree, Binary_Tree, Stack, Design, Binary_Search_Tree, Iterator, Data_Structure_II_Day_17_Tree, Programming_Skills_II_Day_16, Level_2_Day_9_Binary_Search_Tree 563 46.91
0172 Factorial Trailing Zeroes Medium Top_Interview_Questions, Math, Udemy_Integers 220 67.65
0171 Excel Sheet Column Number Easy Top_Interview_Questions, String, Math 310 30.68
0169 Majority Element Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Sorting, Counting, Divide_and_Conquer, Data_Structure_II_Day_1_Array, Udemy_Famous_Algorithm 460 51.25
0168 Excel Sheet Column Title Easy String, Math 208 66.07
0167 Two Sum II - Input Array Is Sorted Medium Array, Binary_Search, Two_Pointers, Algorithm_I_Day_3_Two_Pointers, Binary_Search_I_Day_7 403 68.74
0166 Fraction to Recurring Decimal Medium Top_Interview_Questions, String, Hash_Table, Math 147 90.91
0165 Compare Version Numbers Medium String, Two_Pointers 144 100.00
0164 Maximum Gap Hard Array, Sorting, Bucket_Sort, Radix_Sort 991 68.00
0162 Find Peak Element Medium Top_Interview_Questions, Array, Binary_Search, Algorithm_II_Day_2_Binary_Search, Binary_Search_II_Day_12 297 53.85
0160 Intersection of Two Linked Lists Easy Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Two_Pointers, Linked_List, Data_Structure_II_Day_11_Linked_List, Udemy_Linked_List 262 83.50
0155 Min Stack Easy Top_100_Liked_Questions, Top_Interview_Questions, Stack, Design, Data_Structure_II_Day_14_Stack_Queue, Programming_Skills_II_Day_18, Level_2_Day_16_Design, Udemy_Design 331 84.88
0154 Find Minimum in Rotated Sorted Array II Hard Array, Binary_Search, Binary_Search_II_Day_13 275 84.00
0153 Find Minimum in Rotated Sorted Array Medium Top_100_Liked_Questions, Array, Binary_Search, Algorithm_II_Day_2_Binary_Search, Binary_Search_I_Day_12, Udemy_Binary_Search 262 60.96
0152 Maximum Product Subarray Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Dynamic_Programming_I_Day_6, Level_2_Day_13_Dynamic_Programming, Udemy_Dynamic_Programming 253 88.42
0151 Reverse Words in a String Medium String, Two_Pointers, Udemy_Strings 206 98.90
0150 Evaluate Reverse Polish Notation Medium Top_Interview_Questions, Array, Math, Stack, Programming_Skills_II_Day_3 233 88.82
0149 Max Points on a Line Hard Top_Interview_Questions, Array, Hash_Table, Math, Geometry, Algorithm_II_Day_21_Others 307 83.33
0148 Sort List Medium Top_100_Liked_Questions, Top_Interview_Questions, Sorting, Two_Pointers, Linked_List, Divide_and_Conquer, Merge_Sort, Level_2_Day_4_Linked_List 820 61.70
0147 Insertion Sort List Medium Sorting, Linked_List 385 52.00
0146 LRU Cache Medium Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Design, Linked_List, Doubly_Linked_List, Udemy_Linked_List 1116 97.93
0145 Binary Tree Postorder Traversal Easy Depth_First_Search, Tree, Binary_Tree, Stack, Data_Structure_I_Day_10_Tree, Udemy_Tree_Stack_Queue 211 80.00
0144 Binary Tree Preorder Traversal Easy Depth_First_Search, Tree, Binary_Tree, Stack, Data_Structure_I_Day_10_Tree, Udemy_Tree_Stack_Queue 277 37.90
0143 Reorder List Medium Two_Pointers, Stack, Linked_List, Recursion, Data_Structure_II_Day_13_Linked_List, Programming_Skills_II_Day_14 395 82.26
0142 Linked List Cycle II Medium Top_100_Liked_Questions, Hash_Table, Two_Pointers, Linked_List, Data_Structure_II_Day_10_Linked_List, Level_1_Day_4_Linked_List, Udemy_Linked_List 192 63.39
0141 Linked List Cycle Easy Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Two_Pointers, Linked_List, Data_Structure_I_Day_7_Linked_List, Udemy_Linked_List 223 91.85
0140 Word Break II Hard Top_Interview_Questions, String, Hash_Table, Dynamic_Programming, Backtracking, Trie, Memoization 287 44.19
0139 Word Break Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Dynamic_Programming, Trie, Memoization, Algorithm_II_Day_15_Dynamic_Programming, Dynamic_Programming_I_Day_9, Udemy_Dynamic_Programming 197 87.17
0138 Copy List with Random Pointer Medium Top_100_Liked_Questions, Top_Interview_Questions, Hash_Table, Linked_List, Programming_Skills_II_Day_14, Udemy_Linked_List 274 80.58
0137 Single Number II Medium Array, Bit_Manipulation 344 64.29
0136 Single Number Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Bit_Manipulation, Data_Structure_II_Day_1_Array, Algorithm_I_Day_14_Bit_Manipulation, Udemy_Integers 344 83.63
0135 Candy Hard Array, Greedy 466 58.33
0134 Gas Station Medium Top_Interview_Questions, Array, Greedy 545 70.18
0133 Clone Graph Medium Hash_Table, Depth_First_Search, Breadth_First_Search, Graph, Udemy_Graph 351 60.91
0132 Palindrome Partitioning II Hard String, Dynamic_Programming 290 100.00
0131 Palindrome Partitioning Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Backtracking 820 87.27
0130 Surrounded Regions Medium Top_Interview_Questions, Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find, Algorithm_II_Day_8_Breadth_First_Search_Depth_First_Search 355 84.42
0129 Sum Root to Leaf Numbers Medium Depth_First_Search, Tree, Binary_Tree 237 52.50
0128 Longest Consecutive Sequence Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Union_Find 460 97.77
0127 Word Ladder Hard Top_Interview_Questions, String, Hash_Table, Breadth_First_Search, Graph_Theory_I_Day_12_Breadth_First_Search 396 98.68
0126 Word Ladder II Hard String, Hash_Table, Breadth_First_Search, Backtracking 418 51.45
0125 Valid Palindrome Easy Top_Interview_Questions, String, Two_Pointers, Udemy_Two_Pointers 353 52.06
0124 Binary Tree Maximum Path Sum Hard Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Depth_First_Search, Tree, Binary_Tree, Udemy_Tree_Stack_Queue 331 74.42
0123 Best Time to Buy and Sell Stock III Hard Array, Dynamic_Programming 585 95.24
0122 Best Time to Buy and Sell Stock II Medium Top_Interview_Questions, Array, Dynamic_Programming, Greedy, Dynamic_Programming_I_Day_7, Udemy_Arrays 197 95.10
0121 Best Time to Buy and Sell Stock Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Data_Structure_I_Day_3_Array, Dynamic_Programming_I_Day_7, Level_1_Day_5_Greedy, Udemy_Arrays 609 94.06
0120 Triangle Medium Array, Dynamic_Programming, Algorithm_I_Day_12_Dynamic_Programming, Dynamic_Programming_I_Day_13, Udemy_Dynamic_Programming 194 97.87
0119 Pascal's Triangle II Easy Array, Dynamic_Programming, Data_Structure_II_Day_3_Array, Dynamic_Programming_I_Day_12, Udemy_Dynamic_Programming 157 97.27
0118 Pascal's Triangle Easy Top_Interview_Questions, Array, Dynamic_Programming, Data_Structure_I_Day_4_Array, Dynamic_Programming_I_Day_12, Udemy_Dynamic_Programming 277 33.22
0117 Populating Next Right Pointers in Each Node II Medium Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Linked_List, Algorithm_II_Day_7_Breadth_First_Search_Depth_First_Search 199 94.67
0116 Populating Next Right Pointers in Each Node Medium Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Linked_List, Algorithm_I_Day_8_Breadth_First_Search_Depth_First_Search 355 69.02
0115 Distinct Subsequences Hard String, Dynamic_Programming 285 88.89
0114 Flatten Binary Tree to Linked List Medium Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree, Stack, Linked_List, Udemy_Linked_List 191 93.10
0113 Path Sum II Medium Depth_First_Search, Tree, Binary_Tree, Backtracking, Data_Structure_II_Day_16_Tree 364 78.67
0112 Path Sum Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Data_Structure_I_Day_12_Tree 322 36.41
0111 Minimum Depth of Binary Tree Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Udemy_Tree_Stack_Queue 525 90.51
0110 Balanced Binary Tree Easy Depth_First_Search, Tree, Binary_Tree, Programming_Skills_II_Day_2, Level_2_Day_6_Tree, Udemy_Tree_Stack_Queue 310 63.63
0109 Convert Sorted List to Binary Search Tree Medium Tree, Binary_Tree, Linked_List, Binary_Search_Tree, Divide_and_Conquer 376 59.26
0108 Convert Sorted Array to Binary Search Tree Easy Top_Interview_Questions, Array, Tree, Binary_Tree, Binary_Search_Tree, Divide_and_Conquer, Data_Structure_II_Day_15_Tree, Level_2_Day_9_Binary_Search_Tree, Udemy_Tree_Stack_Queue 334 35.39
0107 Binary Tree Level Order Traversal II Medium Breadth_First_Search, Tree, Binary_Tree 204 98.04
0106 Construct Binary Tree from Inorder and Postorder Traversal Medium Array, Hash_Table, Tree, Binary_Tree, Divide_and_Conquer 358 61.29
0105 Construct Binary Tree from Preorder and Inorder Traversal Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Tree, Binary_Tree, Divide_and_Conquer, Data_Structure_II_Day_15_Tree 370 58.31
0104 Maximum Depth of Binary Tree Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Data_Structure_I_Day_11_Tree, Programming_Skills_I_Day_10_Linked_List_and_Tree, Udemy_Tree_Stack_Queue 236 83.39
0103 Binary Tree Zigzag Level Order Traversal Medium Top_Interview_Questions, Breadth_First_Search, Tree, Binary_Tree, Data_Structure_II_Day_15_Tree, Udemy_Tree_Stack_Queue 316 34.25
0102 Binary Tree Level Order Traversal Medium Top_100_Liked_Questions, Top_Interview_Questions, Breadth_First_Search, Tree, Binary_Tree, Data_Structure_I_Day_11_Tree, Level_1_Day_6_Tree, Udemy_Tree_Stack_Queue 332 67.53
0101 Symmetric Tree Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Data_Structure_I_Day_11_Tree, Level_2_Day_15_Tree 190 91.36
0100 Same Tree Easy Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Level_2_Day_15_Tree, Udemy_Tree_Stack_Queue 208 72.24
0099 Recover Binary Search Tree Medium Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree 492 39.39
0098 Validate Binary Search Tree Medium Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree, Data_Structure_I_Day_14_Tree, Level_1_Day_8_Binary_Search_Tree, Udemy_Tree_Stack_Queue 330 41.38
0097 Interleaving String Medium String, Dynamic_Programming 240 57.50
0096 Unique Binary Search Trees Medium Top_100_Liked_Questions, Dynamic_Programming, Math, Tree, Binary_Tree, Binary_Search_Tree, Dynamic_Programming_I_Day_11 147 88.52
0095 Unique Binary Search Trees II Medium Dynamic_Programming, Tree, Binary_Tree, Backtracking, Binary_Search_Tree 360 41.38
0094 Binary Tree Inorder Traversal Easy Top_100_Liked_Questions, Top_Interview_Questions, Depth_First_Search, Tree, Binary_Tree, Stack, Data_Structure_I_Day_10_Tree, Udemy_Tree_Stack_Queue 269 38.80
0093 Restore IP Addresses Medium String, Backtracking 304 73.33
0092 Reverse Linked List II Medium Linked_List 191 82.35
0091 Decode Ways Medium Top_Interview_Questions, String, Dynamic_Programming, Algorithm_II_Day_15_Dynamic_Programming, Dynamic_Programming_I_Day_10 237 76.88
0090 Subsets II Medium Array, Bit_Manipulation, Backtracking, Algorithm_II_Day_9_Recursion_Backtracking 366 58.09
0089 Gray Code Medium Math, Bit_Manipulation, Backtracking 273 100.00
0088 Merge Sorted Array Easy Top_Interview_Questions, Array, Sorting, Two_Pointers, Data_Structure_I_Day_2_Array 311 33.40
0087 Scramble String Hard String, Dynamic_Programming 366 85.00
0086 Partition List Medium Two_Pointers, Linked_List 172 94.00
0085 Maximal Rectangle Hard Array, Dynamic_Programming, Matrix, Stack, Monotonic_Stack 463 55.17
0084 Largest Rectangle in Histogram Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Stack, Monotonic_Stack 525 100.00
0083 Remove Duplicates from Sorted List Easy Linked_List, Data_Structure_I_Day_8_Linked_List 274 77.82
0082 Remove Duplicates from Sorted List II Medium Two_Pointers, Linked_List, Data_Structure_II_Day_11_Linked_List, Algorithm_II_Day_3_Two_Pointers 241 91.04
0081 Search in Rotated Sorted Array II Medium Array, Binary_Search, Binary_Search_II_Day_12 352 42.31
0080 Remove Duplicates from Sorted Array II Medium Array, Two_Pointers, Udemy_Arrays 357 44.78
0079 Word Search Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Matrix, Backtracking, Algorithm_II_Day_11_Recursion_Backtracking 463 68.49
0078 Subsets Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Bit_Manipulation, Backtracking, Algorithm_II_Day_9_Recursion_Backtracking, Udemy_Backtracking/Recursion 191 97.44
0077 Combinations Medium Backtracking, Algorithm_I_Day_11_Recursion_Backtracking 244 100.00
0076 Minimum Window Substring Hard Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Sliding_Window, Level_2_Day_14_Sliding_Window/Two_Pointer 346 85.20
0075 Sort Colors Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Two_Pointers, Data_Structure_II_Day_2_Array, Udemy_Arrays 198 85.66
0074 Search a 2D Matrix Medium Top_100_Liked_Questions, Array, Binary_Search, Matrix, Data_Structure_I_Day_5_Array, Algorithm_II_Day_1_Binary_Search, Binary_Search_I_Day_8, Level_2_Day_8_Binary_Search, Udemy_2D_Arrays/Matrix 290 40.17
0073 Set Matrix Zeroes Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Matrix, Udemy_2D_Arrays/Matrix 255 100.00
0072 Edit Distance Hard Top_100_Liked_Questions, String, Dynamic_Programming, Algorithm_II_Day_18_Dynamic_Programming, Dynamic_Programming_I_Day_19, Udemy_Dynamic_Programming 320 63.53
0071 Simplify Path Medium String, Stack 318 64.44
0070 Climbing Stairs Easy Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Memoization, Algorithm_I_Day_12_Dynamic_Programming, Dynamic_Programming_I_Day_2, Level_1_Day_10_Dynamic_Programming, Udemy_Dynamic_Programming 127 97.06
0069 Sqrt(x) Easy Top_Interview_Questions, Math, Binary_Search, Binary_Search_I_Day_4 153 95.75
0068 Text Justification Hard Array, String, Simulation 269 50.00
0067 Add Binary Easy String, Math, Bit_Manipulation, Simulation, Programming_Skills_II_Day_5 327 32.67
0066 Plus One Easy Top_Interview_Questions, Array, Math, Programming_Skills_II_Day_3, Udemy_Arrays 303 35.18
0065 Valid Number Hard String 310 81.82
0064 Minimum Path Sum Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Matrix, Dynamic_Programming_I_Day_16, Udemy_Dynamic_Programming 222 95.70
0063 Unique Paths II Medium Array, Dynamic_Programming, Matrix, Dynamic_Programming_I_Day_15 187 84.62
0062 Unique Paths Medium Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Combinatorics, Algorithm_II_Day_13_Dynamic_Programming, Dynamic_Programming_I_Day_15, Level_1_Day_11_Dynamic_Programming 209 49.18
0061 Rotate List Medium Two_Pointers, Linked_List, Programming_Skills_II_Day_16, Udemy_Linked_List 193 92.16
0060 Permutation Sequence Hard Math, Recursion 146 100.00
0059 Spiral Matrix II Medium Array, Matrix, Simulation, Data_Structure_II_Day_3_Array 153 100.00
0058 Length of Last Word Easy String, Programming_Skills_II_Day_6, Udemy_Arrays 243 63.33
0057 Insert Interval Medium Array, Level_2_Day_17_Interval 257 99.52
0056 Merge Intervals Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Data_Structure_II_Day_2_Array, Level_2_Day_17_Interval, Udemy_2D_Arrays/Matrix 320 94.22
0055 Jump Game Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Greedy, Algorithm_II_Day_12_Dynamic_Programming, Dynamic_Programming_I_Day_4, Udemy_Arrays 670 66.67
0054 Spiral Matrix Medium Top_Interview_Questions, Array, Matrix, Simulation, Programming_Skills_II_Day_8, Level_2_Day_1_Implementation/Simulation, Udemy_2D_Arrays/Matrix 224 62.50
0053 Maximum Subarray Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Divide_and_Conquer, Data_Structure_I_Day_1_Array, Dynamic_Programming_I_Day_5, Udemy_Famous_Algorithm 662 82.48
0052 N-Queens II Hard Backtracking 231 80.00
0051 N-Queens Hard Top_100_Liked_Questions, Array, Backtracking 243 95.10
0050 Pow(x, n) Medium Top_Interview_Questions, Math, Recursion, Udemy_Integers 264 52.98
0049 Group Anagrams Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, String, Hash_Table, Sorting, Data_Structure_II_Day_8_String, Programming_Skills_II_Day_11, Udemy_Strings 506 86.55
0048 Rotate Image Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Math, Matrix, Data_Structure_II_Day_3_Array, Programming_Skills_II_Day_7, Udemy_2D_Arrays/Matrix 287 46.50
0047 Permutations II Medium Array, Backtracking, Algorithm_II_Day_10_Recursion_Backtracking 406 76.36
0046 Permutations Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Backtracking, Algorithm_I_Day_11_Recursion_Backtracking, Level_2_Day_20_Brute_Force/Backtracking, Udemy_Backtracking/Recursion 186 100.00
0045 Jump Game II Medium Top_100_Liked_Questions, Array, Dynamic_Programming, Greedy, Algorithm_II_Day_13_Dynamic_Programming, Dynamic_Programming_I_Day_4 227 98.14
0044 Wildcard Matching Hard Top_Interview_Questions, String, Dynamic_Programming, Greedy, Recursion, Udemy_Dynamic_Programming 401 86.11
0043 Multiply Strings Medium String, Math, Simulation, Data_Structure_II_Day_8_String, Programming_Skills_II_Day_4, Level_2_Day_2_String 390 56.25
0042 Trapping Rain Water Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Two_Pointers, Stack, Monotonic_Stack, Dynamic_Programming_I_Day_9, Udemy_Two_Pointers 196 100.00
0041 First Missing Positive Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Udemy_Arrays 345 100.00
0040 Combination Sum II Medium Array, Backtracking, Algorithm_II_Day_10_Recursion_Backtracking 348 80.92
0039 Combination Sum Medium Top_100_Liked_Questions, Array, Backtracking, Algorithm_II_Day_10_Recursion_Backtracking, Level_2_Day_20_Brute_Force/Backtracking, Udemy_Backtracking/Recursion 317 86.85
0038 Count and Say Medium Top_Interview_Questions, String 317 41.11
0037 Sudoku Solver Hard Array, Matrix, Backtracking 294 79.69
0036 Valid Sudoku Medium Top_Interview_Questions, Array, Hash_Table, Matrix, Data_Structure_I_Day_5_Array 346 65.03
0035 Search Insert Position Easy Top_100_Liked_Questions, Array, Binary_Search, Algorithm_I_Day_1_Binary_Search, Binary_Search_I_Day_2 267 50.32
0034 Find First and Last Position of Element in Sorted Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search, Algorithm_II_Day_1_Binary_Search, Binary_Search_I_Day_5 228 83.38
0033 Search in Rotated Sorted Array Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search, Algorithm_II_Day_1_Binary_Search, Binary_Search_I_Day_11, Level_2_Day_8_Binary_Search, Udemy_Binary_Search 184 86.08
0032 Longest Valid Parentheses Hard Top_100_Liked_Questions, String, Dynamic_Programming, Stack 215 95.71
0031 Next Permutation Medium Top_100_Liked_Questions, Array, Two_Pointers 211 94.23
0030 Substring with Concatenation of All Words Hard String, Hash_Table, Sliding_Window 441 85.84
0029 Divide Two Integers Medium Top_Interview_Questions, Math, Bit_Manipulation, Udemy_Bit_Manipulation 281 31.67
0028 Find the Index of the First Occurrence in a String Easy Top_Interview_Questions, String, Two_Pointers, String_Matching, Programming_Skills_II_Day_1 257 32.35
0027 Remove Element Easy Array, Two_Pointers 293 32.19
0026 Remove Duplicates from Sorted Array Easy Top_Interview_Questions, Array, Two_Pointers, Udemy_Two_Pointers 361 77.19
0025 Reverse Nodes in k-Group Hard Top_100_Liked_Questions, Linked_List, Recursion, Data_Structure_II_Day_13_Linked_List, Udemy_Linked_List 194 87.72
0024 Swap Nodes in Pairs Medium Top_100_Liked_Questions, Linked_List, Recursion, Data_Structure_II_Day_12_Linked_List, Udemy_Linked_List 149 99.39
0023 Merge k Sorted Lists Hard Top_100_Liked_Questions, Top_Interview_Questions, Heap_Priority_Queue, Linked_List, Divide_and_Conquer, Merge_Sort 323 75.14
0022 Generate Parentheses Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Backtracking, Algorithm_II_Day_11_Recursion_Backtracking, Udemy_Backtracking/Recursion 210 78.51
0021 Merge Two Sorted Lists Easy Top_100_Liked_Questions, Top_Interview_Questions, Linked_List, Recursion, Data_Structure_I_Day_7_Linked_List, Algorithm_I_Day_10_Recursion_Backtracking, Level_1_Day_3_Linked_List, Udemy_Linked_List 176 96.25
0020 Valid Parentheses Easy Top_100_Liked_Questions, Top_Interview_Questions, String, Stack, Data_Structure_I_Day_9_Stack_Queue, Udemy_Strings 226 72.53
0019 Remove Nth Node From End of List Medium Top_100_Liked_Questions, Top_Interview_Questions, Two_Pointers, Linked_List, Algorithm_I_Day_5_Two_Pointers, Level_2_Day_3_Linked_List 180 91.58
0018 4Sum Medium Array, Sorting, Two_Pointers 221 100.00
0017 Letter Combinations of a Phone Number Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Backtracking, Algorithm_II_Day_11_Recursion_Backtracking, Udemy_Backtracking/Recursion 262 73.59
0016 3Sum Closest Medium Array, Sorting, Two_Pointers, Level_2_Day_14_Sliding_Window/Two_Pointer 413 95.05
0015 3Sum Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Two_Pointers, Data_Structure_II_Day_1_Array, Algorithm_II_Day_3_Two_Pointers, Udemy_Two_Pointers 761 90.55
0014 Longest Common Prefix Easy Top_Interview_Questions, String, Level_2_Day_2_String, Udemy_Strings 209 88.86
0013 Roman to Integer Easy Top_Interview_Questions, String, Hash_Table, Math 358 75.16
0012 Integer to Roman Medium String, Hash_Table, Math 223 93.87
0011 Container With Most Water Medium Top_100_Liked_Questions, Top_Interview_Questions, Array, Greedy, Two_Pointers, Algorithm_II_Day_4_Two_Pointers 474 89.18
0010 Regular Expression Matching Hard Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Recursion, Udemy_Dynamic_Programming 292 58.58
0009 Palindrome Number Easy Math, Udemy_Integers 238 96.24
0008 String to Integer (atoi) Medium Top_Interview_Questions, String 196 96.46
0007 Reverse Integer Medium Top_Interview_Questions, Math, Udemy_Integers 245 60.32
0006 Zigzag Conversion Medium String 366 80.62
0005 Longest Palindromic Substring Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Dynamic_Programming, Data_Structure_II_Day_9_String, Algorithm_II_Day_14_Dynamic_Programming, Dynamic_Programming_I_Day_17, Udemy_Strings 323 75.48
0004 Median of Two Sorted Arrays Hard Top_100_Liked_Questions, Top_Interview_Questions, Array, Binary_Search, Divide_and_Conquer 355 83.48
0003 Longest Substring Without Repeating Characters Medium Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Sliding_Window, Algorithm_I_Day_6_Sliding_Window, Level_2_Day_14_Sliding_Window/Two_Pointer, Udemy_Strings 258 91.09
0002 Add Two Numbers Medium Top_100_Liked_Questions, Top_Interview_Questions, Math, Linked_List, Recursion, Data_Structure_II_Day_10_Linked_List, Programming_Skills_II_Day_15 417 50.44
0001 Two Sum Easy Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Data_Structure_I_Day_2_Array, Level_1_Day_13_Hashmap, Udemy_Arrays 234 92.75

Contributing

Your ideas/fixes/algorithms are more than welcome!

  1. Fork this repo
  2. Clone your forked repo (git clone https://github.com/YOUR_GITHUB_USERNAME/LeetCode-in-Kotlin.git) onto your local machine
  3. cd into your cloned directory, create your feature branch (git checkout -b my-awesome-fix)
  4. git add your desired changes to this repo
  5. Commit your changes (git commit -m 'Added some awesome features/fixes')
  6. Push to the branch (git push origin my-awesome-feature)
  7. Open your forked repo on Github website, create a new Pull Request to this repo!