Python/C Solutions for Leetcode

#	Title	Category	Difficulty	Solution	Time	Space
1528	Shuffle String	Sort	Easy	python, c++	O(N)	O(N)
350	Intersection of Two Arrays II	Hash Table, Two Pointer, Binary Search	Easy	python	O(N)	O(N)
206	Reverse Linked List	Linked List, Recursion	Easy	python, c++	O(N)	O(1)
1640	Check Array Formation Through Concatenation	Array, Hash Table, Sort	Easy	python	O(N)	O(N)
957	Prison Cells After N Days	Hash Table	Medium	python, c++	O(1)	O(1)
1502	Can Make Arithmetic Progression From Sequence	Arrya, Sort	Easy	python	O(NlogN)	O(1)
242	Valid Anagram	Hash Table, Sort	Easy	python	O(N)	O(1)
1450	Number of Students Doing Homework at a Given Time	Array	Easy	python	O(N)	O(1)
1600	Throne Inheritance	Tree, Design	Medium	python	O(N)	O(N^2)
1742	Maximum Number of Balls in a Box	Array	Easy	python	O(N)	O(1)
1054	Distant Barcodes	Heap, Sort	Medium	python	O(N)	O(N)
1464	Maximum Product of Two Elements in an Array	Array	Easy	python	O(N)	O(1)
1725	Number Of Rectangles That Can Form The Largest Square	Greedy	Easy	python	O(N)	O(N)
452	Minimum Number of Arrows to Burst Balloons	Greedy, Sort	Medium	python	O(NlogN)	O(1)
1403	Minimum Subsequence in Non-Increasing Order	Greedy, Sort	Easy	python	O(N)	O(1)
1665	Minimum Initial Energy to Finish Tasks	Greedy	Hard	python	O(NlogN)	O(1)
455	Assign Cookies	Greedy	Easy	python, c++	O(NlogN)	O(1)
1138	Alphabet Board Path	Hash Table, String	Medium	python, c++	O(N)	O(1)
852	Peak Index in a Mountain Array	Binary Search	Easy	python	O(logN)	O(1)
1207	Unique Number of Occurrences	Hash Table	Easy	python	O(N)	O(N)
1122	Relative Sort Array	Array, Sort	Easy	python	O(NM)	O(N)
1160	Find Words That Can Be Formed by Characters	Array, Hash Table	Easy	python, c++	O(N*M)	O(1)
1031	Maximum Sum of Two Non-Overlapping Subarrays	Array	Medium	python	O(N)	O(1)
1491	Average Salary Excluding the Minimum and Maximum Salary	Array, Sort	Easy	python	O(N)	O(1)
283	Move Zeroes	Array, Two Pointers	Easy	python	O(N)	O(1)
445	Add Two Numbers II	Linked List	Medium	python	O(N)	O(N)
2	Add Two Numbers	Linked List	Medium	python, c++	O(N)	O(1)
1254	Number of Closed Islands	Depth-first Search	Medium	python	O(NM)	O(1)
1507	Reformat Date	String	Easy	python	O(1)	O(1)
721	Accounts Merge	Depth-first Search, Union Find	Medium	python	O(NM)	O(NM)
1103	Distribute Candies to People	Math	Easy	python	O(N)	O(N)
202	Happy Number	Hash Table, Math	Easy	python, c	O(1)	O(1)
1710	Maximum Units on a Truck	Greedy, Hash, Sort	Easy	python	O(N)	O(1)
1	Two Sum	Array, Hash	Easy	c, c++	O(N)	O(N)
9	Palindrome Number	Math	Easy	python	O(N)	O(N)
35	Search Insert Position	Array, Binary Search	Easy	python	O(logN)	O(1)
66	Plus One	Array, Math	Easy	python	O(N)	O(N)
83	Remove Duplicates from Sorted List	Linked List	Easy	python	O(N)	O(1)
94	Binary Tree Inorder Traversal	Stack, Tree, DFS, Binary Tree	Easy	python	O(N)	O(N)
13	Roman to Integer	Hash Table, Math, String	Easy	C++	O(N)	O(1)
26	Remove Duplicates from Sorted Array	Array, Two Pointers	Easy	python	O(N)	O(1)
122	Best Time to Buy and Sell Stock II	Array, Dynamic Programming, Gredy	Medium	python	O(N)	O(N)
136	Single Number	Array, Bit Manipulation	Easy	c	O(N)	O(1)
15	3Sum	Array, Two Pointer, Sorting	Medium	python, c++	O(N^2)	O(N)
169	Majority Element	Array, Hash Table, Divide and Conquer	Easy	python, c++	O(N)	O(1)
1470	Running Sum of 1d Array	Array	Easy	python	O(N)	O(1)
724	Find Pivot Index	Array	Easy	python, c++	O(N)	O(1)
205	Isomorphic Strings	Array	Easy	python, c++	O(N)	O(1)
392	Is Subsequence	Two Pointers, String, Dynamic Programming	Easy	python, c++	O(N)	O(1)
14	Longest Common Prefix	String, Trie	Easy	python, c++	O(M*N)	O(1)
704	Binary Search	Array, Binary Search	Easy	python, c, c++	O(log(N))	O(1)
278	First Bad Version	Binary Search, Interfactive	Easy	pythonc	O(log(N))	O(1)
35	Search Instert Position	Array, Binary Search	Easy	python	O(log(N))	O(1)
977	Squares of a Sorted Array	Array, Two Pointers, Sorting	Easy	python	O(N)	O(1)
189	Rotate Array	Array, Math, Two Pointers	Medium	python	O(N)	O(N)
167	Two Sum II - Input Array Is Sorted	Array, Two Pointers, Binary Search	Medium	python	O(N)	O(1)
344	Reverse String	Two Pointers, String	Easy	python, c++	O(N)	O(1)
557	Reverse Words in a String III	Two Pointers, String	Easy	python	O(N^2)	O(N)
876	Middle of the Linked List	Linked List, Two Pointers	Easy	c	O(N)	O(1)
19	Remove Nth Node From End of List	Linked List, Two Pointers	Medium	c, c++	O(N)	O(1)
3	Longest Substring Without Repeating Characters	Hash Table, String, Sliding Window	Medium	c, c++	O(N)	O(1)
209	Minimum Size Subarray Sum	Array, Binary Search, Sliding Window	Medium	c	O(N)	O(1)
219	Contains Duplicate II	Array, Hash Table, Sliding Window	Easy	c++	O(N)	O(M)
220	Contains Duplicate III	Array, Sliding Window, Sorting, Bucket Sort, Ordered Set	Hard	c++	O(N)	O(N)
221	Maximal Square	Array, Dynamic Programming, Matrix	Medium	c++	O(N)	O(N)
213	House Robber II	Array, Dynamic Programming	Medium	c++	O(N)	O(N)
474	Ones and Zeroes	Array, String, Dynamic Programming	Medium	c++	O(N*M*L)	O(N*M)
494	Ones and Zeroes	Array, Dynamic Programming, Backtracking	Medium	c++	O(N*T)	O(N*T)
322	Coin Change	Array, Dynamic Programming, DFS	Medium	c++	O(N*M)	O(M)
518	Coin Change II	Array, Dynamic Programming	Medium	c++	O(N*M)	O(M)
62	Unique Path	Array, Dynamic Programming, Combinatorics	Medium	c++	O(N*M)	O(N*M)
63	Unique Path II	Array, Dynamic Programming	Medium	c++	O(N*M)	O(N*M)
46	Permutations	Array, Backtracking	Medium	c++	O(N*N!)	O(N)
47	Permutations II	Array, Backtracking	Medium	c++	O(N*N!)	O(N)
78	Subsets	Array, Backtracking, Bit Manipulation	Medium	c++	O(N*2^N^)	O(N)
90	Subsets II	Array, Backtracking, Bit Manipulation	Medium	c++	O(N*2^N^)	O(N)
33	Serach in Rotated Sorted Array	Array, Binary Search	Medium	c++	O(log(N))	O(1)
70	Climbing Stairs	Math, Dynamic Programming, Memorization	Easy	c++	O(N)	O(N)
27	Remove Elements	Array, Two Pointers	Easy	c++	O(N)	O(1)
1796	Second Largest Digit in a String	Hash Table, String	Easy	c++	O(N)	O(1)
1540	Can Convert String in K Moves	Hash Table, String	Easy	c++	O(N)	O(1)
2465	Numbers of Distinct Averages	Array, Hash Table, Two Pointers, Sorting	Easy	c++	O(N)	O(1)
2006	Count Number of Pairs With Absolute Difference K	Array, Hash Table	Easy	c++	O(N)	O(N)
100	Same Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Easy	c++	O(1)	O(1)
101	Symmetric Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Easy	c++	O(log(N))	O(1)
104	Maximum Depth of Binary Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Easy	c++	O(N)	O(N)
108	Convert Sorted Array to Binary Search Tree	Array, Divide-And-Conquer, Tree ,Breadth-First Search, Binary Tree	Easy	c++	O(N)	O(N)
110	Balanced Binary Tree	Array, Divide-And-Conquer, Tree ,Breadth-First Search, Binary Tree	Easy	c++	O(N)	O(1)
112	Path Sum	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Easy	c++	O(N)	O(1)
118	Pascal's Triangle	Array, Dynamic Programming	Easy	c++	O(N^2)	O(N^2)
121	Best Time to Buy and Sell Stock	Array, Dynamic Programming	Easy	c++	O(N)	O(1)
509	Fibonacci Number	Dynamic Programming, Recursion, Memorization	Easy	c++	O(N)	O(N)
122	Best Time to Buy and Sell Stock II	Array, Dynamic Programming	Medium	c++	O(N)	O(1)
125	Valid Palindrome	Two Pointers, String	Easy	c++	O(N)	O(1)
141	Linked List Cycle	Hash Table, Linked List, Two Pointers	Easy	c++	O(N)	O(1)
144	Binary Tree Preorder Traversal	Stack, Tree, Detph-First Search, Binary Tree	Easy	c++	O(N)	O(N)
171	Excel Sheet Column Number	Math, String	Easy	c++	O(N)	O(1)
168	Excel Sheet Column Title	Math, String	Easy	c++	O(N)	O(N)
190	Reverse Bits	Divide and Conquer, Bit Manipulation	Easy	c++	O(1)	O(1)
191	Number of 1 Bits	Divide and Conquer, Bit Manipulation	Easy	c++	O(1)	O(1)
203	Remove Linked List Elements	Linked List, Recursion	Easy	c++	O(N)	O(1)
912	Sort an Array	Array, Divide and Conquer, Sorting, Heap (Priority Queue), Merge Sort, Bucket Sort, Radix Sort, Counting Sort	Easy	c++	O(NLogN)	O(N)
217	Contains Duplicate	Array, Hash Table, Sorting	Easy	c++	O(N)	O(N)
222	Count Complete Tree Nodes	Binary Search, Bit Manipulation, Tree, Binary Tree	Easy	c++	O(N)	O(1)
2215	Find the Difference of Two Arrays	Array, Hash Tables	Easy	c++	O(N)	O(N)
1217	Minimum Cost to Move Chips to The Same Position	Array, Math, Greedy	Easy	c++	O(N)	O(1)
2578	Split With Minimum Sum	Math, Greedy, Sorting	Easy	c++	O(1)	O(1)
46	Permutations	Array, Backtracking	Medium	c++	O(N*N!)	O(N)
118	Pascal's Triangle	Array, Dynamic Programming	Easy	c++	O(N^2)	O(N^2)
48	Rotate Image	Array, Math, Matrix	Medium	c++	O(N*2)	O(1)
136	Single Number	Array, Bit Mainulation	Easy	c++	O(N)	O(1)
108	Convert Sorted Array to Binary Search Tree	Array, Divide-And-Conquer, Tree ,Breadth-First Search, Binary Tree	Easy	c++	O(N)	O(N)
289	Game of Life	Array, Matrix, Simulation	Easy	c++	O(MN^2)	O(MN)
49	Group of Anagrams	Array, Hash Table, String, Sorting	Medium	c++	O(NKLog(K))	O(N)
215	Kth Largest Element in an Array	Array, Divide and Conquer, Sorting, Heap(Priority Queue), Quickselect	Easy	c++	O(NlogK)	O(K)
122	Best Time to Buy and Sell Stock II	Array, Dynamic Programming, Greedy	Medium	c++	O(N)	O(1)
238	Product of Array Except Self	Array, Prefix Sum	Medium	c++	O(N)	O(1)
268	Missing Number	Array, Hash Table, Math, Binary Search, Bit Manipulation, Sorting	Easy	c++	O(N)	O(1)
169	Majority Element	Array, Hash Table, Divide and Conquer, Sorting, Counting	Easy	c++	O(N)	O(1)
105	Construct Binary Tree from Preorder and Inorder Traversal	Array, Hash Table, Divide and Conquer, Tree, Binary Tree	Medium	c++	O(N)	O(N)
347	Top K Frequent Elements	Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect	Medium	c++	O(NLogN)	O(N)
378	Kth Smallest Element in a Sorted Matrix	Array, Binary Search, Sorting, Heap (Priority Queue), Matrix	Medium	c++	O(NNlogN)	O(1)
75	Sort Colors	Array, Two Pointers, Sorting	Medium	c++	O(N+M)	O(M)
287	Find the Duplicated Number	Array, Two Pointers, Binary Search, Bit Manipulation	Medium	c++	O(N)	O(1)
200	Number of Islands	Array, Depth-First Search, Breadth-First Search, Union Find, Matrix	Medium	c++	O(N^2)	O(1)
384	Shuffle an Array	Array, Math, Ramdomized	Medium	c++	O(N)	O(N)
454	4Sum II	Array, Hash Table	Medium	c++	O(N^2)	O(N^2)
18	4Sum	Array, Two Pointers, Sorting	Medium	c++	O(N^3)	O(1)
300	Longest Increasing Subsequence	Array, Binary Search, Dynamic Programming	Medium	c++	O(N^2)	O(N)
11	Container With Most Water	Array, Two Pointers, Greedy	Medium	c++	O(N)	O(1)
73	Set Matrix Zeroes	Array, Hash Table, Matrix	Medium	c++	O(NM+V)	O(V)
380	Insert Delete GetRandom O(1)	Array, Hash Table, Math, Design, Randomized	Medium	c++	O(1)	O(N)
329	Longest Increasing Path in a Matrix	Array, Dynamic Programming, Depth-First Search, Breadth-First Search, Graph, Topological Sort, Memoization, Matrix	Hard	c++	O(NM)	O(NM)
240	Search a 2D Matrix II	Array, Binary Search, Divide and Conquer, Matrix	Medium	c++	O(NLogM)	O(1)
198	House Robber	Array, Dynamic Programming	Medium	c++	O(N)	O(1)
150	Evaluate Reverse Polish Notation	Array, Math, Stack	Medium	c++	O(N)	O(N)
88	Merge Sorted Array	Array, Two Pointers, Sorting	Easy	c++	O(N)	O(1)
54	Spiral Matrix	Array, Matrix, Simulation	Medium	c++	O(NM)	O(NM)
128	Longest Consecutive Sequence	Array, Hash Table, Union Find	Medium	c++	O(N^2)	O(N)
140	Word Break II	Array, Hash Table, String, Dynamic Programming, Memoization	Hard	c++	O(NM)	O(N)
56	Merge Intervals	Array, Sorting	Medium	c++	O(NLogN)	O(N)
139	Word Break	Array, Hash Table, String, Dynamic Programming, Trie, Memoization	Medium	c++	O(NM)	O(N)
239	Sliding Window Maximum	Array, Queue, Sliding Window, Heap (Priority Queue), Monotonic Queue	Medium	c++	O(N)	O(N)
162	Find Peak Element	Array, Binary Search	Medium	c++	O(logN)	O(1)
134	Gas Station	Array, Greedy	Medium	c++	O(N)	O(1)
34	Find First and Last Position of Element in Sorted Array	Array, Binary Search	Medium	c++	O(logN)	O(1)
79	Word Search	Array, String, Backtracking, Matrix	Medium	c++	O(NMK)	O(1)
334	Increasing Triplet Subsequence	Array, Greedy	Medium	c++	O(N)	O(1)
130	Surrounded Regions	Array, Depth-First Search, Breadth-First Search, Union Find, Matrix	Medium	c++	O(NM)	O(1)
55	Jump Game	Array, Dynamic Programming, Greedy	Medium	c++	O(N)	O(N)
179	Largest Number	Array, String, Greedy, Sorting	Medium	c++	O(NlogN)	O(N)
152	Maximum Product Subarray	Array, Dynamic Programming	Medium	c++	O(N)	O(N)
324	Wiggle Sort II	Array, Divide and Conquer, Sorting, Quickselect	Medium	c++	O(NlogN)	O(N)
204	Count Primes	Array, Math, Enumeration, Number Theory	Medium	c++	O(NlogN)	O(N)
149	Max Points on a Line	Array, Hash Table, Math, Geometry	Hard	c++	O(N^2)	O(N)
208	Implement Trie (Prefix Tree)	Hash Table, String, Design, Trie	Medium	c++	O(N)	O(N)
212	Word Search II	Array, String, Backtracking, Trie, Matrix	Hard	c++	O(NMK)	O(K)
41	Find Missing Postive	Array, Hash Table	Hard	c++	O(N)	O(1)
146	LRU Cache	Hash Table, Linked List, Design, Doubly-Linked List	Medium	c++	O(1)	O(N)
91	Decode Ways	String, Dynamic Programming	Medium	c++	O(N)	O(N)
5	Longest Palindromic Substring	String, Dynamic Programming	Medium	c++	O(N^2)	O(N)
22	Generate Parentheses	String, Dynamic Programming, Backtracking	Medium	c++	O(2^N)	O(N)
2824	Count Pairs Whose Sum is Less than Target	Array, Two Pointers, Binary Search, Sorting	Easy	c++	O(NlogN)	O(1)
475	Heaters	Array, Two Pointers, Binary Search, Sorting	Medium	c++	O(NlogM)	O(1)
1343	Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold	Array, Sliding Window	Medium	c++	O(N)	O(1)
1347	Minimum Number of Steps to Make Two Strings Anagram	Hash Table, String, Counting	Medium	c++	O(N)	O(1)
894	All Possible Full Binary Trees	Dynamic Programming, Tree, Recursion, Memoization, Binary Tree	Medium	c++	O(N)	O(N)
1641	Count Sorted Vowel Strings	Math, Dynamic Programming, Combinatorics	Medium	c++	O(N)	O(1)
242	Valid Anagram	Hash Table, String, Sorting	Easy	c++	O(N)	O(N)
36	Valid Sudoku	Array, Hash Table, Matrix	Medium	c++	O(1)	O(1)
20	Valid Parentheses	String, Stack	Easy	c++	O(N)	O(N)
155	Min Stack	Stack, Design	Medium	c++	O(1)	O(N)
739	Daily Temperatures	Array, Stack, Monotonic Stack	Medium	c++	O(N)	O(N)
853	Car Fleet	Array, Stack, Sorting, Monotonic Stack	Medium	c++	O(NlogN)	O(N)
496	Next Greater Element I	Array, Hash Table, Stack, Monotonic Stack	Medium	c++	O(N+M)	O(M)
907	Sum of Subarray Minimums	Array, Dynamic Programming, Stack, Monotonic Stack	Medium	c++	O(N)	O(N)
84	Largest Rectangle in Histogram	Array, Stack, Monotonic Stack	Hard	c++	O(N)	O(N)
167	Two Sum II - Input Array Is Sorted	Array, Two Pointers, Binary Search	Medium	c++	O(N)	O(1)
42	Trapping Rain Water	Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack	Hard	c++	O(N)	O(N)
74	Search a 2D Matrix	Array, Binary Search, Matrix	Medium	c++	O(log(N*M))	O(1)
874	Koko Eating Bananas	Array, Binary Search	Medium	c++	O(Nlog(V))	O(1)
981	Time Based Key-Value Store	Hash Table, String, Binary Search, Design	Medium	c++	O(log(N))	O(N)
4	Median of Two Sorted Arrays	Array, Binary Search, Divide and Conquer	Hard	c++	O(log(NM))	O(1)
1588	Sum of All Odd Length Subarrays	Array, Math, Prefix Sum	Easy	c++	O(N)	O(1)
2384	Largest Palindromic Number	Hash Table, String, Greedy	Medium	c++	O(N)	O(N)
464	Can I Win	Math, Dynamic Programming, Bit Manipulation, Memoization, Game Theory, Bitmask	Medium	c++	O(2^N)	O(10^N)
424	Longest Repeating Character Replacement	Hash Table, String, Sliding Window	Medium	c++	O(N)	O(1)
567	Permutation in String	Hash Table, Two Pointers, String, Sliding Window	Medium	c++	O(N)	O(1)
76	Minimum Window Substring	Hash Table, String, Sliding Window	Hard	c++	O(N)	O(1)
21	Merge Two Sorted Lists	Linked List, Recursion	Easy	c++	O(N)	O(1)
143	Reorder List	Linked List, Two Pointers, Stack, Recursion	Medium	c++	O(N)	O(N)
138	Copy List with Random Pointer	Hash Table, Linked List	Medium	c++	O(N)	O(N)
142	Linked List Cycle II	Hash Table, Linked List, Two Pointers	Medium	c++	O(N)	O(1)
23	Merge k Sorted Lists	Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort	Hard	c++	O(NlogK)	O(K)
25	Reverse Nodes in k-Group	Linked List, Recursion	Hard	c++	O(N)	O(1)
763	Partition Labels	Hash Table, Two Pointers, String, Greedy	Medium	c++	O(N)	O(N)
226	Invert Binary Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Easy	c++	O(N)	O(1)
543	Diameter of Binary Tree	Tree, Depth-First Search, Binary Tree	Easy	c++	O(N)	O(1)
572	Subtree of Another Tree	Tree, Depth-First Search, String Matching, Binary Tree, Hash Function	Easy	c++	O(N)	O(1)
102	Binary Tree Level Order Traversal	Tree, Breadth-First Search, Binary Tree	Medium	c++	O(N)	O(2^D)
235	Lowest Common Ancestor of a Binary Search Tree	Tree, Depth-First Search, Binary Search Tree, Binary Tree	Medium	c++	O(N)	O(1)
199	Binary Tree Right Side View	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Medium	c++	O(N)	O(logN)
1448	Count Good Nodes in Binary Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Medium	c++	O(N)	O(1)
98	Validate Binary Search Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Medium	c++	O(N)	O(1)
1535	Find the Winner of an Array Game	Array, Simulation	Medium	c++	O(N)	O(N)
230	Kth Smallest Element in a BST	Tree, Depth-First Search, Binary Search Tree, Binary Tree	Medium	c++	O(K)	O(1)
124	Binary Tree Maximum Path Sum	Dynamic Programming, Tree, Depth-First Search, Binary Tree	Hard	c++	O(N)	O(1)
297	Serialize and Deserialize Binary Tree	String, Tree, Depth-First Search, Breadth-First Search, Design, Binary Tree	Hard	c++	O(N)	O(N)
211	Design Add and Search Words Data Structure	String, Depth-First Search, Design, Trie	Medium	c++	O(N)	O(N)
703	Kth Largest Element in a Stream	Tree, Design, Binary Search Tree, Heap (Priority Queue), Binary Tree, Data Stream	Easy	c++	O(N)	O(K)
1046	Last Stone Weight	Array, Heap (Priority Queue)	Easy	c++	O(NlogN)	O(N)
973	K Closest Points to Origin	Array, Math, Divide and Conquer, Geometry, Sorting, Heap (Priority Queue), Quickselect	Medium	c++	O(NlogK)	O(K)
621	Task Scheduler	Array, Hash Table, Greedy, Sorting, Heap (Priority Queue), Counting	Medium	c++	O(N)	O(N)
355	Design Twitter	Hash Table, Linked List, Design, Heap (Priority Queue)	Medium	c++	O(K*NlogN)	O(N)
904	Fruit Into Baskets	Array, Hash Table, Sliding Window	Medium	c++	O(N)	O(1)
295	Find Median from Data Stream	Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream	Hard	c++	O(logN)	O(N)
39	Combination Sum	Array, Backtracking	Medium	c++	O(NlogN+K/min)	O(K/min)
40	Combination Sum II	Array, Backtracking	Medium	c++	O(NlogN+M*2^N)	O(N)
131	Palindrome Partitioning	String, Dynamic Programming, Backtracking	Medium	c++	O(N^2)	O(N^2)
17	Letter Combinations of a Phone Number	Hash Table, String, Backtracking	Medium	c++	O(N)	O(N)
746	Min Cost Climbing Stairs	Array, Dynamic Programming	Easy	c++	O(N)	O(N)
51	N-Queens	Array, Backtracking	Hard	c++	O(N!)	O(N)
3112	Minimum Time to Visit Disappearing Nodes	Graph	Medium	c++	O(N^V)	O(N)
3110	Score of a String	String	Easy	c++	O(N)	O(1)
3111	Minimum Rectangles to Cover Points	Array	Medium	c++	O(NlogN)	O(N)
647	Palindromic Substrings	Two Pointers, String, Dynamic Programming	Medium	c++	O(N^2)	O(1)
416	Partition Equal Subset Sum	Array, Dynamic Programming	Medium	c++	O(N^2)	O(N)
695	Max Area of Island	Array, Depth-First Search, Breadth-First Search, Union Find, Matrix	Medium	c++	O(NMK)	O(1)
133	Clone Graph	Hash Table, Depth-First Search, Breadth-First Search, Graph	Medium	c++	O(NV)	O(N)
994	Rotting Oranges	Array, Breadth-First Search, Matrix	Medium	c++	O(NM)	O(NM)
417	Pacific Atlantic Water Flow	Array, Depth-First Search, Breadth-First Search, Matrix	Medium	c++	O(NM)	O(NM)
207	Course Schedule	Depth-First Search, Breadth-First Search, Graph, Topological Sort	Medium	c++	O(N+E)	O(N)
1391	Check if There is a Valid Path in a Grid	Array, Depth-First Search, Breadth-First Search, Union Find, Matrix	Medium	c++	O(N*M)	O(1)
2830	Maximize the Profit as the Salesman	Array, Hash Table, Binary Search, Dynamic Programming, Sorting	Medium	c++	O(MlogM)	O(M)
210	Course Schedule II	Depth-First, Search, Breadth-First Search, Graph, Topological Sort	Medium	c++	O(N+E)	O(N*E)
684	Redundant Connection	Depth-First Search, Breadth-First Search, Union Find, Graph	Medium	c++	O(N)	O(N)
127	Word Ladder	Hash Table, String, Breadth-First Search	Hard	c++	O(WNlogN)	O(N)
1143	Longest Common Subsequence	String, Dynamic Programming	Medium	c++	O(NM)	O(NM)
435	Non-overlapping Intervals	Array, Dynamic Programming, Greedy, Sorting	Medium	c++	O(NlogN)	O(1)
57	Insert Interval	Array	Medium	c++	O(N)	O(N)
309	Best Time to Buy and Sell Stock with Cooldown	Array, Dynamic Programming	Medium	c++	O(N)	O(N)
97	Interleaving String	String, Dynamic Programming	Medium	c++	O(N*M)	O(N*M)
115	Distinct Subsequences	String, Dynamic Programming	Hard	c++	O(N*M)	O(N*M)
72	Edit Distance	String, Dynamic Programming	Hard	c++	O(N*M)	O(N*M)
1705	Maximum Number of Eaten Apples	Array, Greedy, Heap (Priority Queue)	Medium	c++	O(NlogN)	O(N)
1367	Linked List in Binary Tree	Linked List, Tree, Depth-First Search, Breadth-First Search, Binary Tree	Medium	c++	O(N+M)	O(1)
312	Burst Balloons	Array, Dynamic Programming	Hard	c++	O(N^2)	O(N^2)
1851	Minimum Interval to Include Each Query	Array, Binary Search, Line Sweep, Sorting, Heap (Priority Queue)	Hard	c++	O((N+M)logN)	O(N+M)
338	Counting Bits	Dynamic Programming
Bit Manipulation	Easy	c++	O(N)	O(N)
371	Sum of Two Integers	Math, Bit Manipulation	Medium	c++	O(1)	O(1)
7	Reverse Integer	Math	Medium	c++	O(N)	O(1)
252	Meeting Rooms	Intervals	Easy	c++	O(N)	O(1)
253	Meeting Rooms II	Intervals	Easy	c++	O(N^2)	O(N)
53	Maximum Subarray	Array, Divide and Conquer, Dynamic Programming	Medium	c++	O(N)	O(1)
45	Jump Game II	Array, Dynamic Programming, Greedy	Medium	c++	O(N)	O(1)
846	Hand of Straights	Array, Hash Table, Greedy, Sorting	Medium	c++	O(NlogN)	O(N)
1899	Merge Triplets to Form Target Triplet	Array, Greedy	Medium	c++	O(N)	O(N)
678	Valid Parenthesis String	String, Dynamic Programming, Stack, Greedy	Medium	c++	O(N)	O(1)
1509	Minimum Difference Between Largest and Smallest Value in Three Moves	Array, Greedy, Sorting	Medium	c++	O(1)	O(1)
1525	Number of Good Ways to Split a String	Hash Table, String, Dynamic Programming, Bit Manipulation	Medium	c++	O(N)	O(N)
3114	Latest Time You Can Obtain After Replacing Characters	String, Enumeration	Easy	c++	O(1)	O(1)
1200	Minimum Absolute Difference	Array, Sorting	Easy	c++	O(NlogN)	O(N)
1007	Minimum Domino Rotations For Equal Row	Array, Greedy	Medium	c++	O(N)	O(1)
1888	Minimum Number of Flips to Make the Binary String Alternating	String, Dynamic Programming, Greedy, Sliding Window	Medium	c++	O(N)	O(1)
274	H-Index	Array, Sorting, Counting Sort	Medium	c++	O(N)	O(1)
1584	Min Cost to Connect All Points	Array, Union Find, Graph, Minimum Spanning Tree	Medium	c++	O(N^2)	O(N)
743	Network Delay Time	Depth-First Search, Breadth-First Search, Graph, Heap (Priority Queue), Shortest Path	Medium	c++	O(N^2)	O(N^2)
1825	Finding MK Average	Design, Queue, Heap (Priority Queue), Data Stream, Ordered Set	Hard	c++	O(logN)	O(1)
874	Walking Robot Simulation	Array, Hash Table, Simulation	Medium	c++	O(N)	O(N)
2547	Minimum Cost to Split an Array	Array, Hash Table, Dynamic Programming, Counting	Hard	c++	O(N^2)	O(N)
2982	Find Longest Special Substring That Occurs Thrice II	Hash Table, String, Binary Search, Sliding Window, Counting	Medium	c++	O(N)	O(N)
2958	Length of Longest Subarray With at Most K Frequency	Array, Hash Table, Sliding Window	Medium	c++	O(N)	O(N)
359	Logger Rate Limiter	Hash Table, Design, Data Stream	Easy	c++	O(1)	O(N)
2402	Meeting Rooms III	Array, Hash Table, Sorting, Heap (Priority Queue), Simulation	Hard	c++	O(NlogN)	O(N)
1110	Delete Nodes And Return Forest	Array, Hash Table, Tree, Depth-First Search, Binary Tree	Medium	c++	O(V)	O(V)
715	Range Module	Design, Segment Tree, Ordered Set	Hard	c++	O(NlogN)	O(NlogN)
939	Minimum Area Rectangle	Array, Hash Table, Math, Geometry, Sorting	Medium	c++	O(N^2)	O(1)
1101	The Earliest Moment When Everyone Become Friends	Array, Union Find, Sorting	Medium	c++	O(N^2)	O(N)
975	Odd Even Jump	Array, Dynamic Programming, Stack, Monotonic Stack, Ordered Set	Hard	c++	O(NlogN)	O(N)
2863	Maximum Length of Semi-Decreasing Subarrays	Array, Hash Table, Sorting	Medium	c++	O(N)	O(N)
2013	Detect Squares	Array, Hash Table, Design, Counting	Medium	c++	O(N)	O(N)
2458	Height of Binary Tree After Subtree Removal Queries	Array, Tree, Depth-First Search, Breadth-First Search, Binary Tree	Hard	c++	O(V+N)	O(V)
85	Maximal Rectangle	Array, Dynamic Programming, Stack, Matrix, Monotonic Stack	Hard	c++	O(N*M)	O(N)
554	Brick Wall	Array, Hash Table	Medium	c++	O(N*M)	O(N)
2184	Number of Ways to Build Sturdy Brick Wall	Array, Dynamic Programming, Bit Manipulation, Bitmask	Medium	c++	O(2W*H)	O(H*2W)
963	Minimum Area Rectangle II	Array, Math, Geometry	Medium	c++	O(N^2)	O(N^2)
2290	Minimum Obstacle Removal to Reach Corner	Array, Breadth-First Search, Graph, Heap (Priority Queue), Matrix, Shortest Path	Hard	c++	O(N^2)	O(N^2)
655	Print Binary Tree	Tree, Depth-First Search, Breadth-First Search, Binary Tree	Medium	c++	O(V)	O(V)
2316	Count Unreachable Pairs of Nodes in an Undirected Graph	Depth-First Search, Breadth-First, Search, Union Find, Graph	Medium	c++	O(N^2)	O(N)
778	Swim in Rising Water	Array, Binary Search, Depth-First Search, Breadth-First Search, Union Find, Heap (Priority Queue), Matrix	Hard	c++	O(N^2)	O(N^2)
1136	Parallel Courses	Graph, Topological Sort	Medium	c++	O(V+E)	O(V+E)
2115	Find All Possible Recipes from Given Supplies	Array, Hash Table, String, Graph, Topological Sort	Medium	c++	O(NM+K)	O(NM+K)
833	Find And Replace in String	Array, String, Sorting	Medium	c++	O(N+M)	O(M+K)
269	Alien Dictionary	Array, String, Depth-First Search, Breadth-First Search, Graph, Topological Sort	Hard	c++	O(NW+E)	O(N+E)
2122	Recover the Original Array	Array, Hash Table, Sorting, Enumeration	Hard	c++	O(N^2)	O(N)
2973	Find Number of Coins to Place in Tree Nodes	Dynamic Programming, Tree, Depth-First Search, Sorting, Heap (Priority Queue)	Medium	c++	O(E)	O(N+E)
365	Water and Jug Problem	Dynamic Programming, Tree, Depth-First Search, Sorting, Heap (Priority Queue)	Medium	c++	O(E)	O(N+E)
1820	Maximum Number of Accepted Invitations	Array, Backtracking, Matrix	Medium	c++	O(N*M)	O(N)
1756	Design Most Recently Used Queue	Array, Hash Table, Stack, Design, Binary Indexed Tree, Ordered Set	Medium	c++	O(N)	O(N)
1940	Longest Common Subsequence Between Sorted Arrays	Array, Hash Table, Counting	Medium	c++	O(MNlogM)	O(N)
2486	Append Characters to String to Make Subsequence	Two Pointers, String, Greedy	Medium	c++	O(N)	O(1)
1005	Maximize Sum Of Array After K Negations	Array, Greedy, Sorting	Easy	c++	O(NlogN)	O(1)
409	Longest Palindrome	Hash Table, String, Greedy	Easy	c++	O(N)	O(N)
1605	Find Valid Matrix Given Row and Column Sums	Array, Greedy, Matrix	Medium	c++	O(NM)	O(NM)
787	Cheapest Flights Within K Stops	Dynamic Programming, Depth-First Search, Breadth-First Search, Graph, Heap (Priority Queue), Shortest Path	Medium	c++	O(N^2*K)	O(N^2)
2191	Sort the Jumbled Numbers	Array, Sorting	Medium	c++	O(N*(logN + W))	O(N)
1636	Sort Array by Increasing Frequency	Array, Hash Table, Sorting	Easy	c++	O(N)	O(N)
1137	N-th Tribonacci Number	Math, Dynamic Programming, Memoization	Easy	c++	O(N)	O(N)
740	Delete and Earn	Array, Hash Table, Dynamic Programming	Medium	c++	O(NlogN)	O(N)
1929	Concatenation of Array	Array, Simulation	Easy	c++	O(N)	O(N)
1299	Replace Elements with Greatest Element on Right Side	Array	Easy	c++	O(N)	O(1)
58	Length of Last Word	String	Easy	c++	O(N)	O(1)
929	Unique Email Address	Array, Hash Table, String	Easy	c++	O(N)	O(N)
609	Can Place Flowers	Array, Greedy	Easy	c++	O(N)	O(1)
303	Range Sum Query - Immutable	Array, Design, Prefix Sum	Easy	c++	O(N)	O(1)
1189	Maximum Number of Balloons	Hash Table, String, Counting	Easy	c++	O(N)	O(1)
290	Word Pattern	Hash Table, String	Easy	c++	O(N+M)	O(N+M)
706	Design HashMap	Array, Hash Table, Linked List, Design, Hash Function	Easy	c++	O(1)	O(N)
705	Design HashSet	Array, Hash Table, Linked List, Design, Hash Function	Easy	c++	O(1)	O(N)
896	Monotonic Array	Array	Easy	c++	O(N)	O(1)
1512	Number of Good Pairs	Array, Hash Table, Math, Counting	Easy	c++	O(N)	O(N)
119	Pascal's Triangle II	Array, Dynamic Programming	Easy	c++	O(N^2)	O(N)
2264	Largest 3-Same-Digit Number in String	String	Easy	[c++](/c++/2264
)	O(N)	O(N)
1436	Destination City	Array, Hash Table, String	Easy	c++	O(N)	O(N)
1913	Maximum Product Difference Between Two Pairs	Array, Sorting	Easy	c++	O(N)	O(1)
1422	Maximum Score After Splitting a String	String, Prefix Sum	Easy	c++	O(N)	O(1)
1496	Path Crossing	Hash Table, String	Easy	c++	O(N)	O(N)
1758	Minimum Changes To Make Alternating Binary String	String	Easy	c++	O(N)	O(1)
1897	Redistribute Characters to Make All Strings Equal	Hash Table, String, Counting	Easy	c++	O(W*N)	O(1)
1624	Largest Substring Between Two Equal Characters	Hash Table, String	Easy	c++	O(N)	O(1)
1700	Number of Students Unable to Eat Lunch	Array, Stack, Queue, Simulation	Easy	c++	O(N)	O(1)
349	Intersection of Two Arrays	Array, Hash Table, Two Pointers, Binary Search, Sorting	Easy	c++	O(NlogN+MlogM)	O(K)
387	First Unique Character in a String	Hash Table, String, Queue, Counting	Easy	c++	O(N)	O(1)
387	First Unique Character in a String	Hash Table, String, Queue, Counting	Easy	c++	O(N)	O(1)
645	Set Mismatch	Array, Hash Table, Bit Manipulation, Sorting	Easy	c++	O(N)	O(N)
2073	Time Needed to Buy Tickets	Array, Queue, Simulation	Easy	c++	O(N)	O(1)
1608	Special Array With X Elements Greater Than or Equal X	Array, Binary Search, Sorting	Easy	c++	O(NlogN)	O(1)
535	Encode and Decode TinyURL	Hash Table, String, Design, Hash Function	Medium	c++	O(N)	O(N)
560	Subarray Sum Equals K	Array, Hash Table, Prefix Sum	Medium	c++	O(N)	O(N)
1930	Unique Length-3 Palindromic Subsequences	Hash Table, String, Bit Manipulation, Prefix Sum	Medium	c++	O(N^2)	O(N)
1963	Minimum Number of Swaps to Make the String Balanced	Two Pointers, String, Stack, Greedy	Medium	c++	O(N)	O(1)
2001	Number of Pairs of Interchangeable Rectangles	Array, Hash Table, Math, Counting, Number Theory	Medium	c++	O(N)	O(N)
2002	Maximum Product of the Length of Two Palindromic Subsequences	String, Dynamic Programming, Backtracking, Bit Manipulation, Bitmask	Medium	c++	O(N^2)	O(N)
2017	Grid Game	Array, Matrix, Prefix Sum	Medium	c++	O(N)	O(N)
438	Find All Anagrams in a String	Hash Table, String, Sliding Window	Medium	c++	O(N+M)	O(1)
28	Find the Index of the First Occurrence in a String	Two Pointers, String, String Matching	Easy	c++	O(NM)	O(1)
523	Continuous Subarray Sum	Array, Hash Table, Math, Prefix Sum	Medium	c++	O(N)	O(N)
838	Push Dominoes	Two Pointers, String, Dynamic Programming	Medium	c++	O(N)	O(N)
187	Repeated DNA Sequences	Hash Table, String, Bit Manipulation, Sliding Window, Rolling Hash, Hash Function	Medium	c++	O(N)	O(N)
1461	Check If a String Contains All Binary Codes of Size K	Hash Table, String, Bit Manipulation, Rolling Hash, Hash Function	Medium	c++	O(N)	O(N)
304	Range Sum Query 2D - Immutable	Array, Design, Matrix, Prefix Sum	Medium	c++	O(1)	O(N*M)
665	Non-decreasing Array	Array	Medium	c++	O(N)	O(1)
1822	Sign of the Product of an Array	Array, Math	Easy	c++	O(N)	O(1)
126	Word Ladder II	Hash Table, String, Backtracking, Breadth-First Search	Hard	c++	O(N*K)	O(N)
1603	Design Parking System	Design, Simulation, Counting	Easy	c++	O(1)	O(1)
2348	Number of Zero-Filled Subarrays	Array, Math	Medium	c++	O(N)	O(1)
933	Number of Recent Calls	Design, Queue, Data Stream	Easy	c++	O(1)	O(1)
362	Design Hit Counter	Array, Binary Search, Design, Queue, Data Stream	Medium	c++	O(N)	O(1)
649	Dota2 Senate	String, Greedy, Queue	Medium	c++	O(N)	O(N)
1396	Design Underground System	Hash Table, String, Design	Medium	c++	O(1)	O(N)
1768	Merge Strings Alternately	Two Pointers, String	Easy	c++	O(N)	O(N)
2483	Minimum Penalty for a Shop	String, Prefix Sum	Medium	c++	O(N)	O(1)
799	Champagne Tower	Dynamic Programming	Medium	c++	O(N^2)	O(N^2)