- R.I.P. to my old Leetcode repository, where there were
5.7k+stars and2.2k+forks (ever the top 3 in the field). - Since free questions may be even mistakenly taken down by some companies, only solutions will be post on now.
- There are new LeetCode questions every week. I'll keep updating for full summary and better solutions.
- For more problem solutions, you can see my LintCode, GoogleKickStart, GoogleCodeJamIO repositories.
- For more challenging problem solutions, you can also see my GoogleCodeJam, MetaHackerCup repositories.
- Hope you enjoy the journey of learning data structures and algorithms.
- Notes: "🔒" means your subscription of LeetCode premium membership is required for reading the question.
- Bit Manipulation
- Array
- String
- Linked List
- Stack
- Queue
- Binary Heap
- Tree
- Hash Table
- Math
- Sort
- Two Pointers
- Recursion
- Binary Search
- Binary Search Tree
- Breadth-First Search
- Depth-First Search
- Backtracking
- Dynamic Programming
- Greedy
- Graph
- Geometry
- Simulation
- Constructive Algorithms
- Design
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2151 | Maximum Good People Based on Statements | C++ Python | O(n^2 * 2^n) | O(1) | Hard | Bitmasks, Brute Force | |
| 2212 | Maximum Points in an Archery Competition | C++ Python | O(n * 2^n) | O(n) | Medium | Bitmasks, Brute Force | |
| 2220 | Minimum Bit Flips to Convert Number | C++ Python | O(logn) | O(1) | Easy | Bit Manipulation | |
| 2275 | Largest Combination With Bitwise AND Greater Than Zero | C++ Python | O(nlogr) | O(logr) | Medium | Bit Manipulation, Freq Table | |
| 2317 | Maximum XOR After Operations | C++ Python | O(n) | O(1) | Medium | Bit Manipulation, Greedy | |
| 2397 | Maximum Rows Covered by Columns | C++ Python | O(m * n + m * C(n, k)) | O(m) | Medium | Bitmasks, Hakmem Item 175 |
|
| 2411 | Smallest Subarrays With Maximum Bitwise OR | C++ Python | O(n) | O(1) | Medium | Bitmasks, Hash Table | |
| 2419 | Longest Subarray With Maximum Bitwise AND | C++ Python | O(n) | O(1) | Medium | Bit Manipulation | |
| 2425 | Bitwise XOR of All Pairings | C++ Python | O(n) | O(1) | Medium | Bit Manipulation | |
| 2429 | Minimize XOR | C++ Python | O(logn) | O(1) | Medium | Bit Manipulation, Greedy | |
| 2505 | Bitwise OR of All Subsequence Sums | C++ Python | O(n) | O(1) | Medium | 🔒 | Bit Manipulation |
| 2527 | Find Xor-Beauty of Array | C++ Python | O(n) | O(1) | Medium | Bit Manipulation, Math | |
| 2595 | Number of Even and Odd Bits | C++ Python | O(1) | O(1) | Easy | Bit Manipulation |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2058 | Find the Minimum and Maximum Number of Nodes Between Critical Points | C++ Python | O(n) | O(1) | Medium | ||
| 2074 | Reverse Nodes in Even Length Groups | C++ Python | O(n) | O(1) | Medium | ||
| 2095 | Delete the Middle Node of a Linked List | C++ Python | O(n) | O(1) | Medium | Two Pointers | |
| 2130 | Maximum Twin Sum of a Linked List | C++ Python | O(n) | O(1) | Medium | Two Pointers | |
| 2181 | Merge Nodes in Between Zeros | C++ Python | O(n) | O(1) | Medium | Two Pointers | |
| 2487 | Remove Nodes From Linked List | C++ Python | O(n) | O(n) | Medium | Mono Stack | |
| 2674 | Split a Circular Linked List | C++ Python | O(n) | O(1) | Medium | 🔒 | Two Pointers, Slow and Fast Pointers |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2104 | Sum of Subarray Ranges | C++ Python | O(n) | O(n) | Medium | Mono Stack | |
| 2197 | Replace Non-Coprime Numbers in Array | C++ Python | O(nlogm) | O(1) | Hard | Stack, Math | |
| 2281 | Sum of Total Strength of Wizards | C++ Python | O(n) | O(n) | Hard | variant of Largest Rectangle in Histogram | Mono Stack, Prefix Sum |
| 2282 | Number of People That Can Be Seen in a Grid | C++ Python | O(m * n) | O(m + n) | Medium | 🔒, variant of Number of Visible People in a Queue | Mono Stack |
| 2334 | Subarray With Elements Greater Than Varying Threshold | C++ Python | O(n) | O(n) | Hard | variant of Maximum Subarray Min-Product | Mono Stack |
| 2355 | Maximum Number of Books You Can Take | C++ Python | O(n) | O(n) | Hard | 🔒 | Mono Stack, Math |
| 2454 | Next Greater Element IV | C++ Python | O(n) | O(n) | Hard | Mono Stack |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2398 | Maximum Number of Robots Within Budget | C++ Python | O(n) | O(n) | Hard | Mono Deque, Sliding Window, Two Pointers |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2054 | Two Best Non-Overlapping Events | C++ Python | O(nlogn) | O(n) | Medium | Line Sweep, Heap | |
| 2163 | Minimum Difference in Sums After Removal of Elements | C++ Python | O(nlogn) | O(n) | Hard | Heap, Prefix Sum | |
| 2208 | Minimum Operations to Halve Array Sum | C++ Python | O(nlogn) | O(n) | Medium | Heap | |
| 2386 | Find the K-Sum of an Array | C++ Python | O(nlogn + klogk) | O(n + k) | Hard | BFS, Heap | |
| 2402 | Meeting Rooms III | C++ Python | O(mlogm + n + mlogn) | O(n) | Hard | Heap | |
| 2462 | Total Cost to Hire K Workers | C++ Python | O(c + klogc) | O(c) | Medium | Heap, Two Pointers | |
| 2519 | Count the Number of K-Big Indices | C++ Python | O(nlogk) | O(n) | Hard | 🔒 | Heap, Ordered Set, Sorted List |
| 2530 | Maximal Score After Applying K Operations | C++ Python | O(n + klogn) | O(1) | Medium | Heap, Simulation | |
| 2558 | Take Gifts From the Richest Pile | C++ Python | O(n + klogn) | O(1) | Easy | Heap, Simulation |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2003 | Smallest Missing Genetic Value in Each Subtree | C++ Python | O(n) | O(n) | Hard | DFS, Stack | |
| 2096 | Step-By-Step Directions From a Binary Tree Node to Another | C++ Python | O(n) | O(h) | Medium | DFS, Stack | |
| 2179 | Count Good Triplets in an Array | C++ Python | O(nlogn) | O(n) | Hard | variant of Create Sorted Array through Instructions | BIT, Fenwick Tree |
| 2196 | Create Binary Tree From Descriptions | C++ Python | O(n) | O(n) | Medium | ||
| 2236 | Root Equals Sum of Children | C++ Python | O(1) | O(1) | Easy | Tree | |
| 2277 | Closest Node to Path in Tree | C++ Python | O(n + q) | O(n) | Hard | 🔒 | Tree, BFS, Binary Lifting, Tarjan's Offline LCA Algorithm |
| 2421 | Number of Good Paths | C++ Python | O(nlogn) | O(n) | Hard | Sort, Union Find | |
| 2509 | Cycle Length Queries in a Tree | C++ Python | O(q * n) | O(1) | Hard | Tree, LCA |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2001 | Number of Pairs of Interchangeable Rectangles | C++ Python | O(n) | O(n) | Medium | Math | |
| 2005 | Subtree Removal Game with Fibonacci Tree | C++ Python | O(1) | O(1) | Hard | 🔒 | Math, Sprague-Grundy Theorem, Colon Principle |
| 2028 | Find Missing Observations | C++ Python | O(n) | O(1) | Medium | ||
| 2029 | Stone Game IX | C++ Python | O(n) | O(1) | Medium | ||
| 2063 | Vowels of All Substrings | C++ Python | O(n) | O(1) | Medium | Combinatorics | |
| 2073 | Time Needed to Buy Tickets | C++ Python | O(n) | O(1) | Easy | Simulation, Math | |
| 2083 | Substrings That Begin and End With the Same Letter | C++ Python | O(n) | O(1) | Medium | 🔒 | Combinatorics |
| 2091 | Removing Minimum and Maximum From Array | C++ Python | O(n) | O(1) | Medium | Math | |
| 2110 | Number of Smooth Descent Periods of a Stock | C++ Python | O(n) | O(1) | Medium | Math, Combinatorics | |
| 2117 | Abbreviating the Product of a Range | C++ Python | O(r - l) | O(1) | Hard | Math | |
| 2119 | A Number After a Double Reversal | C++ Python | O(1) | O(1) | Easy | Math | |
| 2125 | Number of Laser Beams in a Bank | C++ Python | O(m * n) | O(1) | Medium | Math | |
| 2133 | Check if Every Row and Column Contains All Numbers | C++ Python | O(n^2) | O(n) | Easy | Math | |
| 2145 | Count the Hidden Sequences | C++ Python | O(n) | O(1) | Medium | Math | |
| 2148 | Count Elements With Strictly Smaller and Greater Elements | C++ Python | O(n) | O(1) | Easy | Math | |
| 2152 | Minimum Number of Lines to Cover Points | C++ Python | O(n * 2^n) | O(n^2) | Medium | 🔒 | Math, Hash Table, Bitmasks |
| 2169 | Count Operations to Obtain Zero | C++ Python | O(log(min(m, n))) | O(1) | Easy | Math, Euclidean Algorithm |
|
| 2171 | Removing Minimum Number of Magic Beans | C++ Python | O(nlogn) | O(1) | Medium | Math, Sort | |
| 2176 | Count Equal and Divisible Pairs in an Array | C++ Python | O(nlogk + n * sqrt(k)) | O(n + sqrt(k)) | Easy | Math | |
| 2177 | Find Three Consecutive Integers That Sum to a Given Number | C++ Python | O(1) | O(1) | Medium | Math | |
| 2180 | Count Integers With Even Digit Sum | C++ Python | O(logn) | O(1) | Easy | Math | |
| 2183 | Count Array Pairs Divisible by K | C++ Python | O(nlogk + k) | O(sqrt(k)) | Hard | variant of Count Equal and Divisible Pairs in an Array | Math |
| 2198 | Number of Single Divisor Triplets | C++ Python | O(d^3) | O(d) | Medium | 🔒 | Math, Combinatorics |
| 2217 | Find Palindrome With Fixed Length | C++ Python | O(n * l) | O(1) | Medium | Math | |
| 2221 | Find Triangular Sum of an Array | C++ Python | O(n) | O(1) | Medium | Simulation, Combinatorics, Number Thoery | |
| 2235 | Add Two Integers | C++ Python | O(1) | O(1) | Easy | Math | |
| 2240 | Number of Ways to Buy Pens and Pencils | C++ Python | O(sqrt(t)) | O(1) | Medium | Math | |
| 2244 | Minimum Rounds to Complete All Tasks | C++ Python | O(n) | O(n) | Medium | Math, Freq Table | |
| 2249 | Count Lattice Points Inside a Circle | C++ Python | O(n * r^2) | O(min(n * r^2, max_x * max_y)) | Medium | Math, Hash Table | |
| 2262 | Total Appeal of A String | C++ Python | O(n) | O(26) | Hard | variant of Count Unique Characters of All Substrings of a Given String | Combinatorics |
| 2280 | Minimum Lines to Represent a Line Chart | C++ Python | O(nlogn) | O(1) | Medium | Sort, Math, GCD | |
| 2310 | Sum of Numbers With Units Digit K | C++ Python | O(1) | O(1) | Medium | Math | |
| 2338 | Count the Number of Ideal Arrays | C++ Python | O(sqrt(m) + n + m * (logm + sqrt(m)/log(sqrt(m)))) | O(sqrt(m) + n + logm) | Hard | variant of Count Ways to Make Array With Product | DP, Linear Sieve of Eratosthenes, Factorization, Combinatorics |
| 2344 | Minimum Deletions to Make Array Divisible | C++ Python | O(n + m + logr) | O(1) | Hard | Math, GCD | |
| 2345 | Finding the Number of Visible Mountains | C++ Python | O(nlogn) | O(1) | Medium | 🔒 | Math, Sort, Mono Stack |
| 2376 | Count Special Integers | C++ Python | O(logn) | O(logn) | Hard | variant of Numbers With Repeated Digits | Combinatorics |
| 2396 | Strictly Palindromic Number | C++ Python | O(1) | O(1) | Medium | Math | |
| 2400 | Number of Ways to Reach a Position After Exactly k Steps | C++ Python | O(k) | O(k) | Medium | Combinatorics | |
| 2409 | Count Days Spent Together | C++ Python | O(1) | O(1) | Easy | String, Math, Prefix Sum | |
| 2413 | Smallest Even Multiple | C++ Python | O(1) | O(1) | Easy | Math, Bit Manipulation | |
| 2427 | Number of Common Factors | C++ Python | O(log(min(a, b)) + sqrt(gcd)) | O(1) | Easy | Math | |
| 2437 | Number of Valid Clock Times | C++ Python | O(1) | O(1) | Easy | Combinatorics | |
| 2450 | Number of Distinct Binary Strings After Applying Operations | C++ Python | O(logn) | O(1) | Medium | 🔒 | Combinatorics |
| 2455 | Average Value of Even Numbers That Are Divisible by Three | C++ Python | O(n) | O(1) | Easy | Math | |
| 2468 | Split Message Based on Limit | C++ Python | O(n + rlogr) | O(1) | Hard | Brute Force, Math | |
| 2469 | Convert the Temperature | C++ Python | O(1) | O(1) | Easy | Math | |
| 2481 | Minimum Cuts to Divide a Circle | C++ Python | O(1) | O(1) | Easy | Math | |
| 2485 | Find the Pivot Integer | C++ Python | O(1) | O(1) | Easy | Math | |
| 2514 | Count Anagrams | C++ Python | O(n) | O(n) | Hard | Math, Combinatorics | |
| 2520 | Count the Digits That Divide a Number | C++ Python | O(logn) | O(1) | Easy | Math | |
| 2521 | Distinct Prime Factors of Product of Array | C++ Python | precompute: O(sqrt(MAX_N)) runtime: O(m + nlog(logn)) |
O(sqrt(MAX_N)) | Medium | Number Theory, Linear Sieve of Eratosthenes |
|
| 2523 | Closest Prime Numbers in Range | C++ Python | precompute: O(MAX_N * log(MAX_N)) runtime: O(log(MAX_N)) |
O(MAX_N) | Medium | Number Theory, Linear Sieve of Eratosthenes, Segment Tree |
|
| 2525 | Categorize Box According to Criteria | C++ Python | O(1) | O(1) | Easy | Math | |
| 2539 | Count the Number of Good Subsequences | C++ Python | O(26 * n) | O(n) | Medium | 🔒 | Combinatorics |
| 2543 | Check if Point Is Reachable | C++ Python | O(log(min(a, b))) | O(1) | Hard | Number Theory | |
| 2544 | Alternating Digit Sum | C++ Python | O(logn) | O(1) | Easy | Math | |
| 2549 | Count Distinct Numbers on Board | C++ Python | O(1) | O(1) | Easy | Math | |
| 2550 | Count Collisions of Monkeys on a Polygon | C++ Python | O(logn) | O(1) | Medium | Combinatorics, Fast Exponentiation | |
| 2562 | Find the Array Concatenation Value | C++ Python | O(nlogr) | O(1) | Easy | Math | |
| 2568 | Minimum Impossible OR | C++ Python | O(logr) | O(1) | Medium | Math, Hash Table, Bit Manipulations | |
| 2579 | Count Total Number of Colored Cells | C++ Python | O(1) | O(1) | Medium | Math | |
| 2582 | Pass the Pillow | C++ Python | O(1) | O(1) | Medium | Math | |
| 2584 | Split the Array to Make Coprime Products | C++ Python | O(n * sqrt(r)) | O(sqrt(r)) | Hard | Math, Number Theory | |
| 2614 | Prime In Diagonal | C++ Python | precompute: O(MAX_N) runtime: O(n) |
O(MAX_N) | Easy | Number Theory, Linear Sieve of Eratosthenes |
|
| 2651 | Calculate Delayed Arrival Time | C++ Python | O(1) | O(1) | Easy | Math | |
| 2652 | Sum Multiples | C++ Python | O(1) | O(1) | Easy | Math, Principle of Inclusion and Exclusion | |
| 2656 | Maximum Sum With Exactly K Elements | C++ Python | O(n) | O(1) | Easy | Math |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2015 | Average Height of Buildings in Each Segment | C++ Python | O(nlogn) | O(n) | Medium | 🔒 | Line Sweep |
| 2021 | Brightest Position on Street | C++ Python | O(nlogn) | O(n) | Medium | 🔒 | Line Sweep |
| 2070 | Most Beautiful Item for Each Query | C++ Python | O(nlogn + qlogn) | O(1) | Medium | Sort, Binary Search | |
| 2089 | Find Target Indices After Sorting Array | C++ Python | O(n) | O(1) | Easy | Counting Sort | |
| 2158 | Amount of New Area Painted Each Day | C++ Python | O(nlogr) | O(r) | Hard | 🔒 | Line Sweep, Sorted List, Heap, Segment Tree |
| 2164 | Sort Even and Odd Indices Independently | C++ Python | O(n) | O(c) | Easy | Counting Sort, Inplace | |
| 2191 | Sort the Jumbled Numbers | C++ Python | O(nlogm + nlogn) | O(n) | Medium | Sort | |
| 2231 | Largest Number After Digit Swaps by Parity | C++ Python | O(logn) | O(1) | Easy | Counting Sort | |
| 2233 | Maximum Product After K Increments | C++ Python | O(n + k) | O(n) | Medium | Heap, Freq Table, Sort, Math | |
| 2248 | Intersection of Multiple Arrays | C++ Python | O(n * l + r) | O(l) | Easy | Hash Table, Counting Sort | |
| 2251 | Number of Flowers in Full Bloom | C++ Python | O(nlogn + mlogn) | O(n) | Hard | Line Sweep, Binary Search | |
| 2343 | Query Kth Smallest Trimmed Number | C++ Python | O(q + n * t) | O(t + n + q) | Medium | Sort, Quick Select, Radix Sort | |
| 2418 | Sort the People | C++ Python | O(nlogn) | O(n) | Easy | Sort | |
| 2497 | Maximum Star Sum of a Graph | C++ Python | O(n) | O(n) | Medium | Sort, Quick Select | |
| 2512 | Reward Top K Students | C++ Python | O(pf * l + nf * l + n * l + klogk) | O(pf * l + nf * l + n) | Medium | Partial Sort, Quick Select | |
| 2545 | Sort the Students by Their Kth Score | C++ Python | O(mlogm) | O(1) | Medium | Sort | |
| 2659 | Make Array Empty | C++ Python | O(nlogn) | O(n) | Hard | Sort, BIT, Fenwick Tree | |
| 2679 | Sum in a Matrix | C++ Python | O(m * nlogn) | O(1) | Medium | Sort |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2009 | Minimum Number of Operations to Make Array Continuous | C++ Python | O(nlogn) | O(1) | Hard | Two Pointers, Sliding Window | |
| 2024 | Maximize the Confusion of an Exam | C++ Python | O(n) | O(1) | Medium | variant of Longest Repeating Character Replacement | Sliding Window |
| 2040 | Kth Smallest Product of Two Sorted Arrays | C++ Python | O((m + n) * logr) | O(1) | Hard | Binary Search, Two Pointers | |
| 2046 | Sort Linked List Already Sorted Using Absolute Values | C++ Python | O(n) | O(1) | Medium | 🔒 | Linked List |
| 2062 | Count Vowel Substrings of a String | C++ Python | O(n) | O(1) | Easy | variant of Count Number of Nice Subarrays | Sliding Window |
| 2067 | Number of Equal Count Substrings | C++ Python | O(n) | O(1) | Medium | 🔒 | Sliding Window |
| 2090 | K Radius Subarray Averages | C++ Python | O(n) | O(1) | Medium | Sliding Window | |
| 2105 | Watering Plants II | C++ Python | O(n) | O(1) | Medium | Simulation | |
| 2107 | Number of Unique Flavors After Sharing K Candies | C++ Python | O(n) | O(n) | Medium | 🔒 | Sliding Window |
| 2134 | Minimum Swaps to Group All 1's Together II | C++ Python | O(n) | O(1) | Medium | Sliding Window | |
| 2149 | Rearrange Array Elements by Sign | C++ Python | O(n) | O(1) | Medium | Two Pointers | |
| 2161 | Partition Array According to Given Pivot | C++ Python | O(n) | O(n) | Medium | Two Pointers | |
| 2200 | Find All K-Distant Indices in an Array | C++ Python | O(n) | O(1) | Easy | Two Pointers | |
| 2234 | Maximum Total Beauty of the Gardens | C++ Python | O(nlogn) | O(1) | Hard | Sort, Prefix Sum, Greedy, Binary Search, Two Pointers | |
| 2302 | Count Subarrays With Score Less Than K | C++ Python | O(n) | O(1) | Hard | Two Pointers, Sliding Window | |
| 2330 | Valid Palindrome IV | C++ Python | O(n) | O(1) | Medium | 🔒 | String, Two Pointers |
| 2332 | The Latest Time to Catch a Bus | C++ Python | O(nlogn + mlogm) | O(1) | Medium | String, Two Pointers | |
| 2337 | Move Pieces to Obtain a String | C++ Python | O(n + m) | O(1) | Medium | String, Two Pointers | |
| 2348 | Number of Zero-Filled Subarrays | C++ Python | O(n) | O(1) | Medium | Two Pointers, Combinatorics | |
| 2379 | Minimum Recolors to Get K Consecutive Black Blocks | C++ Python | O(n) | O(1) | Easy | Sliding Window | |
| 2393 | Count Strictly Increasing Subarrays | C++ Python | O(n) | O(1) | Medium | 🔒 | Two Pointers |
| 2401 | Longest Nice Subarray | C++ Python | O(n) | O(1) | Medium | Sliding Window, Two Pointers | |
| 2444 | Count Subarrays With Fixed Bounds | C++ Python | O(n) | O(1) | Hard | variant of Number of Substrings Containing All Three Characters | Two Pointers |
| 2461 | Maximum Sum of Distinct Subarrays With Length K | C++ Python | O(n) | O(k) | Medium | Two Pointers | |
| 2465 | Number of Distinct Averages | C++ Python | O(nlogn) | O(n) | Easy | Two Pointers, Hash Table | |
| 2511 | Maximum Enemy Forts That Can Be Captured | C++ Python | O(n) | O(1) | Easy | Array, Two Pointers | |
| 2516 | Take K of Each Character From Left and Right | C++ Python | O(n) | O(1) | Medium | Sliding Window, Two Pointers | |
| 2524 | Maximum Frequency Score of a Subarray | C++ Python | O(n) | O(n) | Hard | 🔒 | Sliding Window, Two Pointers, Freq Table, Hash Table |
| 2537 | Count the Number of Good Subarrays | C++ Python | O(n) | O(n) | Medium | Sliding Window, Two Pointers | |
| 2540 | Minimum Common Value | C++ Python | O(n) | O(1) | Easy | Two Pointers | |
| 2555 | Maximize Win From Two Segments | C++ Python | O(n) | O(n) | Medium | Two Pointers, Sliding Window, DP | |
| 2563 | Count the Number of Fair Pairs | C++ Python | O(nlogn) | O(1) | Medium | Sort, Two Pointers | |
| 2570 | Merge Two 2D Arrays by Summing Values | C++ Python | O(n) | O(1) | Easy | Two Pointers | |
| 2609 | Find the Longest Balanced Substring of a Binary String | C++ Python | O(n) | O(1) | Easy | String, Two Pointers | |
| 2653 | Sliding Subarray Beauty | C++ Python | O(nlogk) | O(k) | Medium | Sorted List, Ordered Set, Two Pointers |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2613 | Beautiful Pairs | C++ Python | O(n) on average | O(n) | Hard | 🔒, variant of SPOJ - Closest Point Pair | Random Algorithms, Divide and Conquer, Merge Sort, Segment Tree |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2064 | Minimized Maximum of Products Distributed to Any Store | C++ Python | O(nlogm) | O(1) | Medium | variant of Minimum Limit of Balls in a Bag | |
| 2111 | Minimum Operations to Make the Array K-Increasing | C++ Python | O(nlog(n/k)) | O(n/k) | Hard | variant of Longest Increasing Subsequence | |
| 2137 | Pour Water Between Buckets to Make Water Levels Equal | C++ Python | O(nlogr) | O(1) | Medium | 🔒 | |
| 2187 | Minimum Time to Complete Trips | C++ Python | O(nlogr) | O(1) | Medium | ||
| 2226 | Maximum Candies Allocated to K Children | C++ Python | O(nlogr) | O(1) | Medium | Binary Search | |
| 2250 | Count Number of Rectangles Containing Each Point | C++ Python | O(nlogn + m * max_y * logn) | O(n) | Medium | Bucket Sort, Binary Search | |
| 2300 | Successful Pairs of Spells and Potions | C++ Python | O(mlogm + nlogm) | O(1) | Medium | Binary Search | |
| 2333 | Minimum Sum of Squared Difference | C++ Python | O(nlogn + nlogr) | O(1) | Medium | Binary Search | |
| 2387 | Median of a Row Wise Sorted Matrix | C++ Python | O(logr * mlogn) | O(1) | Medium | 🔒 | Binary Search |
| 2389 | Longest Subsequence With Limited Sum | C++ Python | O(nlogn + qlogn) | O(1) | Easy | Greedy, Sort, Binary Search | |
| 2448 | Minimum Cost to Make Array Equal | C++ Python | O(nlogn) | O(n) | Hard | Math, Binary Search, Prefix Sum | |
| 2476 | Closest Nodes Queries in a Binary Search Tree | C++ Python | O(n + qlogn) | O(n) | Hard | DFS, Binary Search | |
| 2513 | Minimize the Maximum of Two Arrays | C++ Python | O(log(min(d1, d2))) | O(1) | Medium | Number Theory, Binary Search | |
| 2517 | Maximum Tastiness of Candy Basket | C++ Python | O(nlogr) | O(1) | Medium | Binary Search, Greedy | |
| 2528 | Maximize the Minimum Powered City | C++ Python | O(nlogk) | O(n) | Hard | Binary Search, Sliding Window, Greedy | |
| 2529 | Maximum Count of Positive Integer and Negative Integer | C++ Python | O(logn) | O(1) | Easy | Binary Search | |
| 2554 | Maximum Number of Integers to Choose From a Range I | C++ Python | O(b) | O(b) | Medium | Math, Binary Search, Prefix Sum, Greedy | |
| 2557 | Maximum Number of Integers to Choose From a Range II | C++ Python | O(b) | O(b) | Medium | 🔒 | Math, Binary Search, Prefix Sum |
| 2560 | House Robber IV | C++ Python | O(nlogn) | O(n) | Medium | Binary Search, Greedy | |
| 2594 | Minimum Time to Repair Cars | C++ Python | O(mx * (logc + log(mn))) | O(mx) | Medium | Freq Table, Binary Search, Heap, Simulation | |
| 2602 | Minimum Operations to Make All Array Elements Equal | C++ Python | O(nlogn + qlogn) | O(n) | Medium | Sort, Binary Search, Prefix Sum | |
| 2616 | Minimize the Maximum Difference of Pairs | C++ Python | O(nlogn + nlogr) | O(1) | Medium | Sort, Binary Search, Greedy |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2426 | Number of Pairs Satisfying Inequality | C++ Python | O(nlogn) | O(n) | Hard | Merge Sort, Two Pointers, BIT, Fenwick Tree, Coordinate Compression, Sorted List, Ordered Set, Binary Search |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2014 | Longest Subsequence Repeated k Times | C++ Python | O(n * (n/k)!) | O(n/k) | Hard | ||
| 2056 | Number of Valid Move Combinations On Chessboard | C++ Python | O(1) | O(1) | Hard | ||
| 2094 | Finding 3-Digit Even Numbers | C++ Python | O(n) | O(1) | Easy | ||
| 2443 | Sum of Number and Its Reverse | C++ Python | O(n^(1/(2*log2(10)))) | O(log10(n)/2) | Medium | Brute Force, Backtracking | |
| 2664 | The Knight’s Tour | C++ Python | O(m * n) | O(1) | Medium | 🔒 | Backtracking, Greedy, Warnsdorff's Rule |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2076 | Process Restricted Friend Requests | C++ Python | O(n * r) | O(n) | Hard | Union Find | |
| 2077 | Paths in Maze That Lead to Same Room | C++ Python | O(|V|^3) | O(|E|) | Medium | 🔒 | |
| 2092 | Find All People With Secret | C++ Python | O(nlogn) | O(nlogn) | Hard | BFS, DFS, Union Find | |
| 2093 | Minimum Path Cost in a Hidden Grid | C++ Python | O(|E| * log|V|) | O(|V| + |E|) | Medium | variant of Cheapest Flights Within K Stops, 🔒 | Dijkstra's Algorithm, DP |
| 2097 | Valid Arrangement of Pairs | C++ Python | O(|V| + |E|) | O(|V| + |E|) | Hard | variant of Reconstruct Itinerary | Hierholzer's Algorithm, Eulerian Path |
| 2123 | Minimum Operations to Remove Adjacent Ones in Matrix | C++ Python | O(m * n * sqrt(m * n)) | O(m + n) | Hard | variant of Maximum Students Taking Exam, 🔒 | Hopcroft-Karp Bipartite Matching, Maximum Independent Set |
| 2127 | Maximum Employees to Be Invited to a Meeting | C++ Python | O(n) | O(n) | Hard | ||
| 2172 | Maximum AND Sum of Array | C++ Python | O(n^3) | O(n^2) | Hard | variant of Maximum Compatibility Score Sum | DP, Hungarian Weighted Bipartite Matching |
| 2203 | Minimum Weighted Subgraph With the Required Paths | C++ Python | O(|E| * log|V|) | O(|E|) | Hard | Dijkstra's Algorithm |
|
| 2204 | Distance to a Cycle in Undirected Graph | C++ Python | O(|V| + |E|) | O(|V| + |E|) | Hard | 🔒 | Graph, DFS, BFS |
| 2242 | Maximum Score of a Node Sequence | C++ Python | O(|V| + |E|) | O(|V|) | Hard | Graph | |
| 2307 | Check for Contradictions in Equations | C++ Python | O(e + q) | O(n) | Hard | 🔒, variant of Evaluate Division | DFS, Union Find |
| 2359 | Find Closest Node to Given Two Nodes | C++ Python | O(n) | O(n) | Medium | Graph, Hash Table, DFS | |
| 2360 | Longest Cycle in a Graph | C++ Python | O(n) | O(n) | Hard | Graph, Hash Table, DFS | |
| 2392 | Build a Matrix With Conditions | C++ Python | O(k^2 + r + c) | O(k + r + c) | Hard | Graph, Topological Sort | |
| 2473 | Minimum Cost to Buy Apples | C++ Python | O(n * rlogn) | O(n) | Medium | 🔒 | Dijkstra's Algorithm |
| 2508 | Add Edges to Make Degrees of All Nodes Even | C++ Python | O(n) | O(n) | Hard | Graph | |
| 2608 | Shortest Cycle in a Graph | C++ Python | O(n^2) | O(n + e) | Hard | Graph, BFS | |
| 2662 | Minimum Cost of a Path With Special Roads | C++ Python | O(n^2) | O(n^2) | Medium | Graph, Dijkstra's Algorithm |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2101 | Detonate the Maximum Bombs | C++ Python | O(|V|^2 + \V| * |E|) | O(\V| + |E|) | Medium | Graph, DFS, BFS |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2061 | Number of Spaces Cleaning Robot Cleaned | C++ Python | O(m * n) | O(1) | Medium | 🔒 | |
| 2162 | Minimum Cost to Set Cooking Time | C++ Python | O(1) | O(1) | Medium | ||
| 2257 | Count Unguarded Cells in the Grid | C++ Python | O(m * n) | O(m * n) | Medium | Array, Simulation | |
| 2303 | Calculate Amount Paid in Taxes | C++ Python | O(n) | O(1) | Easy | Simulation | |
| 2507 | Smallest Value After Replacing With Sum of Prime Factors | C++ Python | O(s * logn) | O(max_n^0.5) | Medium | Number Theory, Simulation | |
| 2532 | Time to Cross a Bridge | C++ Python | O(k + nlogk) | O(k) | Hard | Heap, Simulation | |
| 2534 | Time Taken to Cross the Door | C++ Python | O(n) | O(n) | Hard | 🔒 | Queue, Simulation |
| 2593 | Find Score of an Array After Marking All Elements | C++ Python | O(nlogn) | O(n) | Medium | Simulation, Sort, Hash Table | |
| 2596 | Check Knight Tour Configuration | C++ Python | O(m * n) | O(m * n) | Medium | Simulation, Hash Table | |
| 2682 | Find the Losers of the Circular Game | C++ Python | O(n) | O(n) | Easy | Hash Table, Simulation |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2202 | Maximize the Topmost Element After K Moves | C++ Python | O(min(n, k)) | O(1) | Medium | Constructive Algorithms | |
| 2335 | Minimum Amount of Time to Fill Cups | C++ Python | O(1) | O(1) | Easy | Math, Constructive Algorithms | |
| 2350 | Shortest Impossible Sequence of Rolls | C++ Python | O(n) | O(k) | Hard | Constructive Algorithms | |
| 2546 | Apply Bitwise Operations to Make Strings Equal | C++ Python | O(n) | O(1) | Medium | Constructive Algorithms | |
| 2358 | Maximum Number of Groups Entering a Competition | C++ Python | O(1) | O(1) | Medium | Constructive Algorithms, Math | |
| 2610 | Convert an Array Into a 2D Array With Conditions | C++ Python | O(n) | O(n) | Medium | Freq Table, Constructive Algorithms | |
| 2647 | Color the Triangle Red | C++ Python | O(n^2) | O(1) | Hard | 🔒 | Constructive Algorithms |
| 2654 | Minimum Number of Operations to Make All Array Elements Equal to 1 | C++ Python | O(n^2) | O(1) | Medium | Math, Number Theory, Constructive Algorithms |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2013 | Detect Squares | C++ Python | ctor: O(1) add: O(1) count: O(n) |
O(n) | Medium | ||
| 2034 | Stock Price Fluctuation | C++ Python | ctor: O(1) update: O(logn) current: O(1) max: O(1) min: O(1) |
O(n) | Medium | Sorted List, Heap | |
| 2043 | Simple Bank System | C++ Python | ctor: O(1) transer: O(1) deposit: O(1) withdraw: O(1) |
O(1) | Medium | ||
| 2069 | Walking Robot Simulation II | C++ Python | O(1) | O(1) | Medium | Simulation, Math | |
| 2080 | Range Frequency Queries | C++ Python | ctor: O(n) query: O(logn) |
O(n) | Medium | Binary Search | |
| 2102 | Sequentially Ordinal Rank Tracker | C++ Python | add: O(logn) get: O(logn) |
O(n) | Hard | Sorted List | |
| 2166 | Design Bitset | C++ Python | ctor: O(n) fix: O(1) fix: O(1) unfix: O(1) flip: O(1) all: O(1) one: O(1) count: O(1) toString: O(n) |
O(n) | Medium | ||
| 2227 | Encrypt and Decrypt Strings | C++ Python | ctor: O(m + d) encrypt: O(n) decrypt: O(n) |
O(n) | Hard | Freq Table | |
| 2241 | Design an ATM Machine | C++ Python | ctor: O(1) deposit: O(1) withdraw: O(1) |
O(1) | Medium | Greedy | |
| 2254 | Design Video Sharing Platform | C++ Python | ctor: O(1) upload: O(logn + l) remove: O(logn) like: O(1) dislike: O(1) view: O(1) getLikesAndDislikes: O(1) getViews: O(1) |
O(n * l) | Hard | 🔒 | Heap |
| 2276 | Count Integers in Intervals | C++ Python | ctor: O(1) add: O(logn), amortized Count: O(1) |
O(n) | Hard | Sorted List | |
| 2286 | Booking Concert Tickets in Groups | C++ Python | ctor: O(n) gather: O(logn) scatter: O(logn), amortized |
O(n) | Hard | Segment Tree, Binary Search | |
| 2296 | Design a Text Editor | C++ Python | ctor: O(1) addText: O(l) deleteText: O(k) cursorLeft: O(k) cursorRight: O(k) |
O(n) | Hard | Stack | |
| 2336 | Smallest Number in Infinite Set | C++ Python | ctor: O(1) popSmallest: O(logn) addBack: O(logn) |
O(n) | Medium | Heap, BST | |
| 2349 | Design a Number Container System | C++ Python | ctor: O(1) change: O(logn) find: O(1) |
O(n) | Medium | Sorted List, BST | |
| 2353 | Design a Food Rating System | C++ Python | ctor: O(nlogn) changeRating: O(logn) highestRated: O(1) |
O(n) | Medium | Sorted List, BST | |
| 2408 | Design SQL | C++ Python | ctor: O(t * max_m) insertRow: O(m) deleteRow: O(1) selectCell: O(m) |
O(d) | Medium | 🔒 | Hash Table |
| 2424 | Longest Uploaded Prefix | C++ Python | ctor: O(1) upload: O(1), amortized longest: O(1) |
O(n) | Medium | Hash Table | |
| 2502 | Design Memory Allocator | C++ Python | ctor: O(1) allocate: O(logn) free: O(logn) |
O(n) | Medium | Sorted List | |
| 2526 | Find Consecutive Integers from a Data Stream | C++ Python | O(1) | O(1) | Medium | Array | |
| 2590 | Design a Todo List | C++ Python | ctor: O(1) addTask: O(l + logn) getAllTasks: O(r) getTasksForTag: O(r * c) completeTask: O(l + logn) |
O(n * l) | Medium | 🔒 | BST, Sorted List |
| 2642 | Design Graph With Shortest Path Calculator | C++ Python | ctor: O(|V| + |E|) addEdge: O(1) shortestPath: O(|E| * log|V|) |
O(|E|) | Hard | Dijkstra's Algorithm |
|
| 2671 | Frequency Tracker | C++ Python | ctor: O(1) add: O(1) deleteOne: O(1) hasFrequency: O(1) |
O(min(n, r)) | Medium | Freq Table |
| # | Title | Solution | Time | Space | Difficulty | Tag | Note |
|---|---|---|---|---|---|---|---|
| 2618 | Check if Object Instance of Class | TypeScript | O(n) | O(1) | Medium | ||
| 2619 | Array Prototype Last | TypeScript | O(1) | O(1) | Easy | ||
| 2620 | Counter | TypeScript | O(1) | O(1) | Easy | ||
| 2621 | Sleep | TypeScript | O(1) | O(1) | Easy | Promise | |
| 2622 | Cache With Time Limit | TypeScript | O(1) | O(1) | Medium | Hash Table | |
| 2623 | Memoize | TypeScript | O(1) | O(1) | Medium | Hash Table | |
| 2624 | Snail traversal | TypeScript | O(m * n) | O(1) | Medium | ||
| 2625 | Flatten Deeply Nested Array | TypeScript | O(n) | O(h) | Medium | DFS | |
| 2626 | Array Reduce Transformation | TypeScript | O(n) | O(1) | Easy | ||
| 2627 | Debounce | TypeScript | O(1) | O(1) | Medium | ||
| 2628 | JSON Deep Equal | TypeScript | O(n) | O(h) | Medium | DFS | |
| 2629 | Function Composition | TypeScript | O(n) | O(1) | Easy | ||
| 2630 | Memoize II | TypeScript | O(n) | O(t) | Hard | Trie | |
| 2631 | Group By | TypeScript | O(n) | O(1) | Medium | ||
| 2632 | Curry | TypeScript | O(n) | O(n) | Medium | ||
| 2633 | Convert Object to JSON String | TypeScript | O(n) | O(h) | Medium | DFS | |
| 2634 | Filter Elements from Array | TypeScript | O(n) | O(1) | Easy | ||
| 2635 | Apply Transform Over Each Element in Array | TypeScript | O(n) | O(1) | Easy | ||
| 2636 | Promise Pool | TypeScript | O(c + n / c) | O(c) | Medium | Promise | |
| 2637 | Promise Time Limit | TypeScript | O(n) | O(1) | Easy | Promise | |
| 2648 | Generate Fibonacci Sequence | TypeScript | O(1) | O(1) | Easy | DP | |
| 2649 | Nested Array Generator | TypeScript | O(1) | O(d) | Medium | DFS | |
| 2650 | Design Cancellable Function | TypeScript | O(1) | O(1) | Hard | Promise | |
| 2665 | Counter II | TypeScript | ctor: O(1) increment: O(1) decrement: O(1) reset: O(1) |
O(1) | Easy | ||
| 2666 | Allow One Function Call | TypeScript | O(1) | O(1) | Easy | ||
| 2667 | Create Hello World Function | TypeScript | O(1) | O(1) | Easy | ||
| 2675 | Array of Objects to Matrix | TypeScript | O(l * mlogm + m * n) | O(l * m + m * n) | Medium | DFS | |
| 2676 | Throttle | TypeScript | O(1) | O(1) | Medium | ||
| 2677 | Chunk Array | TypeScript | O(n) | O(1) | Easy |