for practice
- leet code weekly/bi-weekly contest
https://leetcode.com/contest/
weekly/bi-weekly
Glind 75 (Frequent Asked Leetcode problem sets)
https://www.techinterviewhandbook.org/grind75/
NeetCode
https://neetcode.io/practice/practice/neetcode150
| easy | medium | hard |
|---|---|---|
| 148 | 413 | 190 |
- NeetCode
Total solved url_neetcode250
NeetCode all url
--> 151+ solved, 0.8%
| easy | medium | hard |
|---|---|---|
| 26/217 | 52/564 | 149/149 |
-- | - | - | url | |
NeetCode
| No. | 概要 | url | 備考 |
|---|---|---|---|
| Paint House II | A DP that uses the minimum and second minimum from the previous row for each house; define dp[i][c] as the minimum cost to paint houses 0..i with house i painted color c. | url | |
| Minimize Max Distance to Gas Station | Heap(gap/parts)/Binary Search | url | |
| New 21 Game | Probability DP with sliding window | url | |
| Integer Break | Dynamic Programming | url | |
| Minimum Cost For Tickets | Dynamic Programming | url | |
| Perfect Squares | Dynamic Programming | url | |
| Combination Sum IV | Dynamic Programming | url | |
| Triangle | Dynamic Programming | url | |
| Partition Equal Subset Sum | Dynamic Programming | url | |
| Longest Increasing Subsequence | bisect right, list, longest increase subsequence | url | |
| Coin Change | Dynamic Programming | url | |
| Word Break | Dynamic Programming | url | |
| Maximum Product Subarray | Dynamic Programming | url | |
| Decode Ways | dp[i] represents the number of ways to decode the first i characters of the string. | url | |
| Palindromic Substrings | Dynamic Programming | url | |
| Maximum Number of Points with Cost | Dynamic Programming | url | |
| Minimum Path Sum | Dynamic Programming | url | |
| Unique Paths II | Dynamic Programming | url | |
| N-th Tribonacci Number | Dynamic Programming | url | |
| Min Cost Climbing Stairs | Dynamic Programming | url | |
| Climbing Stairs | Dynamic Programming | url | |
| Interval DP, Substring DP, dp[i][j] represents whether substring is palindrome | Dynamic Programming | url | |
| 4 Keys Keyboard | Dynamic Programming | url | |
| Paint Fence | Dynamic Programming | url | |
| Paint House | Dynamic Programming | url | |
| House Robber II | Dynamic Programming + case split | url | |
| House Robber | Dynamic Programming | url | |
| Coin Path | Reverse DP / Path Reconstruction / lexicographical order as a tie-break | url | |
| Encode String with Shortest Length | Interval DP with string pattern compression / optimal substructure | url | |
| Valid Palindrome III | dp[i][j] = minimum deletions needed to make s[i:j+1] a palindrome | url | |
| Optimal Account Balancing | DFS with backtracking and pruning | url | |
| Concatenated Words | lexicographical, compare word[j:i] with DP | url | |
| Sparse Matrix Multiplication | Process Matrix | url | |
| Lonely Pixel I | Count, list | url | |
| Maximum Distance in Arrays | O(n) | url | |
| Append Characters to String to Make Subsequence | while/step by step comparison | url | |
| Rotate Array | reserse 2 times | url | |
| 4Sum | 2-pointer approarch | url | |
| 3Sum | defaultdict | url | |
| Two Integer Sum II | for loop, 2times | url | |
| String Compression | Run-Length Encoding, RLE | url | |
| Logger Rate Limiter | Dictionary | url | |
| Design Compressed String Iterator | Offset | url | |
| Perform String Shifts | Offset | url | |
| Counting Elements | Cnt | url | |
| Palindrome Permutation | collections,Counter | url | |
| Single-Row Keyboard | defaultdict | url | |
| Number of Distinct Islands II | DFS,BFS / Normalization(Sort, Transform) | url | |
| Maximum Number of Ones | Count how much each cell contributes to the total number of ones | url | |
| Best Meeting Point | mean / average | url | |
| Employee Free Time | sort/greedy | url | |
| 2416. Sum of Prefix Scores of Strings | Tri-Tree | url | |
| Design Excel Sum Formula | recursive call | url | |
| Time Taken to Cross the Door | deque / state management / enter,exit | url | |
| 2940. Find Building Where Alice and Bob Can Meet | Heap/ | url | |
| 1425. Constrained Subsequence Sum | Dynamic Programming / Sliding Window Maximum | url | |
| 2251. Number of Flowers in Full Bloom | index compression/counter/set | url | |
| 857. Minimum Cost to Hire K Workers | heap/greedy | url | |
| 1383. Maximum Performance of a Team | heap/greedy | url | |
| 1675. Minimize Deviation in Array | heap/greedy | url | |
| 1028. Recover a Tree From Preorder Traversal | Tree/Traversal | url | |
| Subarrays with K Different Integers | Sliding Window/Boundaries | url | |
| Number of Ships in a Rectangle | Divide and Conquer (Quadtree) | url | |
| Moving Average from Data Stream | class/list | url | |
| Is Subsequence | 2-Pointers | url | |
| Intersection of Two Linked Lists | 2loops in the lists | url | |
| Missing Number | sum/O(1) | url | |
| Best Time to Buy and Sell Stock | min/max/for | url | |
| Shortest Bridge | Multi-Source-BFS | url | |
| Basic Calculator II | Recursive | url | |
| Max Area of Island | BFS | url | |
| Combination Sum II | set(taple)/dynamic programming | url | |
| Course Schedule | Toporogical sort | url | |
| Reorganize String | Heap | url | |
| Merge Intervals | Sort | url | |
| Number of Islands | BFS/DFS | url | |
| Letter Combinations of a Phone Number | BackTrack | url | |
| Design Circular Queue | Circular Queue/EnQueue,DeQueue | url | |
| Longest Substring Without Repeating Characters | Sliding Windows | url | |
| Design Tic-Tac-Toe | Brute Force | url | |
| Minimum Knight Moves | BFS | url | |
| Meeting Rooms II | Event Sort(座標圧縮) | url | |
| Serialize and Deserialize N-ary Tree | DFS/Deserialize,serialize** | url | |
| Maximum Average Subarray II | Binary Search /Average-to-Sum Transformation/Offset Values/Accumulated Sum | url | |
| The Maze III | Dijkstra/Heap/Dict Structure** | url | |
| Basic Calculator III | Caluculation(+-*/()/Stack,Recursion) | url | |
| Bus Routes | Node Management/BFS on a dual-layer graph, prioritizing routes as nodes to reduce search space. | url | |
| Split Array With Same Average | A bitset-optimized dynamic programming approach to solve the Subset Sum Problem.** | url | |
| Design Search Autocomplete System | Tri-Tree/Search Autocomplete text | url | |
| Closest Binary Search Tree Value II | Two-Stack BST Iterator/Binary Search | url | |
| Divide Chocolate | Binary Search/Greedy Check | url | |
| Maximum Profit in Job Scheduling | DP with Binary Search | url | |
| Max Stack | Heap/Lazy Removal | url | |
| Rearrange String k Distance Apart | Greedy with Cooling Queue/Greedy Approach using Max-Priority Queue and Deque | url | |
| Text Justification | Greedy Word Packing/Greedy Round-robin space distribution | url | |
| Put Marbles in Bags | Adjacent Pair Sum Maximization/Minimization | url | |
| Design In-Memory File System | Tri-Tree | url | |
| Cherry Pickup | Synchronized Two-Player Pathfinding | url | |
| Minimum Number of Increments on Subarrays to Form a Target Array | brute_force/increment | url | |
| Russian Doll Envelopes | sort/bisect | url | |
| K-th Smallest in Lexicographical Order | Calculate k-th smallest number with the subtree strategy | url | |
| Shortest Distance from All Buildings | BFS/manage the distance from each buildings | url | |
| Number of Visible People in a Queue | Monotonic-Stack | url | |
| Number of Islands II | Union-Find | url | |
| Greatest Common Divisor Traversal | Prime Factorization, Union-Find | url | |
| Build a Matrix With Conditions | Topological sort, row*col | url | |
| Find Critical and Pseudo Critical Edges in Minimum Spanning Tree | Graph Critical/Pseudo Critical Edges/UnionFind+Sort | url | |
| Alien Dictionary | BFS / Kahn's Algorithm, toporogical sort | url | |
| Swim in Rising Water | Binary Search+BFS/Dijkstra | url | |
| Distinct Subsequences | Dynamic Programming | url | |
| Burst Balloons | Top-down Dynamic Programming with Memoization | url | |
| Regular Expression Matching | DP | url | |
| Minimum Interval to Include Each Query | heap/sort | url | |
| Meeting Rooms III | heap | url | |
| Word Break II | DP | url | |
| N-Queens II | BFS | url | |
| First Missing Positive | swap,O(n) | url | |
| Meeting Rooms III | manage used,available with heapq | url | |
| Candy | brute force algorithm | url | |
| Longest Increasing Path in Matrix | BFS, calculate the contributed value | url | |
| Stone Game III | dp, bottom up | url | |
| Reconstruct Flight Path | stack,pop,dfs | url | |
| Word Ladder | BFS | url | |
| Word Search II | Trie Tree | url | |
| N-Queens | Recursive, (r,c) | url | |
| IPO | Project, Heap(log(N)) | url | |
| Find Median From Data Stream | 2 heaps | url | |
| Serialize and Deserialize Binary Tree | Tree, Search | url | |
| Binary Tree Maximum Path Sum | Tree, recursive, Accumulate the contributions | url | |
| Reverse Nodes in K-Group | Linked Lists/Recursive,reverse | url | |
| Merge K Sorted Linked Lists | Linked Lists | url | |
| LFU Cache | Least Frequency Used Cache/OrderedDict | url | |
| Find in Mountain Array | Binary Search | url | |
| Median of Two Sorted Arrays | Binary search/left,right array | url | |
| Split Array Largest Sum | Binary Search | url | |
| Largest Rectangle In Histogram | Check the high,low value/for | url | |
| Maximum Frequency Stack | manage stack value | url | |
| Sliding Window Maximum | Put the maximum num in the front of que always | url | |
| Minimum Window Substring | Window Search, based on r | url | |
| Trapping Rain Water | 2 pointer | url | |
| Two Sum | for | url | |
| Valid Anagram | sort | url | |
| Contains Duplicate | set | url | |
| Longest Consecutive Sequence | set | url | |
| Valid Sudoku | for | url | |
| Products of Array Except Self | accumulated sum | url | |
| Encode and Decode Strings | special charactor | url | |
| Top K Frequent Elements | freq | url | |
| Group Anagrams | compare the orger of strings | url |
LeetCode
| No. | 概要 | url | 備考 |
|---|---|---|---|
| 1147. Longest Chunked Palindrome Decomposition | dfs | url | |
| 1125. Smallest Sufficient Team | Bit DP | url | |
| 1301. Number of Paths with Max Score | 2D DP | url | |
| 1278. Palindrome Partitioning III | Interval DP | url | |
| 1312. Minimum Insertion Steps to Make a String Palindrome | Interval DP | url | |
| 3739. Count Subarrays With Majority Element II | Fenwick Tree | url | |
| 3020. Find the Maximum Number of Elements in Subset | Greedy + Counter | url | |
| 1846. Maximum Element After Decreasing and Rearranging | sort | url | |
| 3020. Find the Maximum Number of Elements in Subset | count | url | |
| 1833. Maximum Ice Cream Bars | sort | url | |
| 1189. Maximum Number of Balloons | defaultdict | url | |
| 1840. Maximum Building Height | Compute the maximum height between restriction points. | url | |
| 1732. Find the Highest Altitude | max(),gain | url | |
| 1344. Angle Between Hands of a Clock | Transform from minutes to angle | url | |
| 2095. Delete the Middle Node of a Linked List | fast,slow pointer | url | |
| 1000. Minimum Cost to Merge Stones | Interval DP | url | |
| 960. Delete Columns to Make Sorted III | 2strings, dp | url | |
| 964. Least Operators to Express Number | dp,Digit DP on the base-x representation. | url | |
| 968. Binary Tree Cameras | dfs, dp | url | |
| 975. Odd Even Jump | odd,even,dp | url | |
| 996. Number of Squareful Arrays | squared, bfs, Counter | url | |
| 3838. Weighted Word Mapping | ord('a'),chr('a'),for,mod | url | |
| 2130. Maximum Twin Sum of a Linked List | LinkedList | url | |
| 3559. Number of Ways to Assign Edge Weights II | BFS / dp | url | |
| 3558. Number of Ways to Assign Edge Weights I | BFS | url | |
| 2161. Partition Array According to Given Pivot | list | url | |
| 956. Tallest Billboard | Difference DP | url | |
| 943. Find the Shortest Superstring | string / BitDP / brute force | url | |
| 3753. Total Waviness of Numbers in Range II | BitDP | url | |
| 2574. Left and Right Sum Differences | sum | url | |
| 3635. Earliest Finish Time for Land and Water Rides II | Prefix,Suffix / BinarySearch | url | |
| 903. Valid Permutations for DI Sequence | DP / rank | url | |
| 913. Cat and Mouse | DP / Backward Propagation of Game Outcomes | url | |
| 940. Distinct Subsequences II | DP | url | |
| 887. Super Egg Drop | Inverse DP / Reverse DP | url | |
| 902. Numbers At Most N Given Digit Set | digit DP | url | |
| 871. Minimum Number of Refueling Stops | greedy / heapq | url | |
| 834. Sum of Distances in Tree | Tree / Re-rooting DP | url | |
| 847. Shortest Path Visiting All Nodes | BFS / bitMask | url | |
| 828. Count Unique Characters of All Substrings of a Given String | Count contributions | url | |
| 818. Race Car | DP / 2 patterns | url | |
| 2126. Destroying Asteroids | sort | url | |
| 688. Knight Probability in Chessboard | dp / probability | url | |
| 678. Valid Parenthesis String | dp / O(n) | url | |
| 673. Number of Longest Increasing Subsequence | dp / LIS | url | |
| 650. 2 Keys Keyboard | dp / prime factorization | url | |
| 3161. Block Placement Queries | update only the portions affected by inserting a new obstacle | url | |
| 741. Cherry Pickup | DP | url | |
| 801. Minimum Swaps To Make Sequences Increasing | DP | url | |
| 3093. Longest Common Suffix Queries | Tri Tree | url | |
| 664. Strange Printer | interval DP / dfs | url | |
| 730. Count Different Palindromic Subsequences | interval DP | url | |
| 600. Non-negative Integers without Consecutive Ones | Digit D＋ Fibonacci | url | |
| 639. Decode Ways II | 2 types of transition | url | |
| 3120. Count the Number of Special Characters I | defaultdict / c.lower | url | |
| 472. Concatenated Words | DP / consecutive word[j:i] | url | |
| 647. Palindromic Substrings | Expand Around Center | url | |
| 458. Poor Pigs | state | url | |
| 466. Count The Repetitions | Repeated subsequence matching with cycle detection | url | |
| 472. Concatenated Words | Word Break DP | url | |
| 410. Split Array Largest Sum | binary search | url | |
| 403. Frog Jump | DP with reachable jump sizes per stone, Jump forward | url | |
| 354. Russian Doll Envelopes | sort+Longest Increasing Subsequence | url | |
| 329. Longest Increasing Path in a Matrix | Topological DP | url | |
| 312. Burst Balloons | Interval DP | url | |
| 233. Number of Digit One | Digit Counting (count the number of 1s at each place value) | url | |
| 188. Best Time to Buy and Sell Stock IV | Dynamic Programming (Transaction-based State DP) | url | |
| 174. Dungeon Game | # Define dp[i][j] as the minimum HP required when entering room (i, j), then compute it in reverse order. | url | |
| 140. Word Break II | dp[] / dp[i] = all valid sentences that can form s[:i] (the first i characters | url | |
| 132. Palindrome Partitioning II | palindrome[j][i] / dp | url | |
| 123. Best Time to Buy and Sell Stock III | dp / accumlated sum | url | |
| 115. Distinct Subsequences | dp, string from backward | url | |
| 87. Scramble String | recursive call | url | |
| 44. Wildcard Matching | dp, string | url | |
| 10. Regular Expression Matching | dp, 2 dimension | url | |
| 32. Longest Valid Parentheses | stack | url | |
| 646. Maximum Length of Pair Chain | greedy chain | url | |
| 638. Shopping Offers | DFS with Memoization | url | |
| 583. Delete Operation for Two Strings | lcs | url | |
| 576. Out of Boundary Paths | BFS | url | |
| 553. Optimal Division | O(1) | url | |
| 1340. Jump Game V | dfs | url | |
| 526. Beautiful Arrangement | bitmask DP | url | |
| 518. Coin Change II | Unbounded Knapsack DP | url | |
| 516. Longest Palindromic Subsequence | Interval DP | url | |
| 486. Predict the Winner | MinMax | url | |
| 473. Matchsticks to Square | Bitmask DP | url | |
| 464. Can I Win | Minimax + DFS + Memoization | url | |
| 467. Unique Substrings in Wraparound String | dp/unique subsequence number | url | |
| 413. Arithmetic Slices | greedy | url | |
| 397. Integer Replacement | greedy | url | |
| 375. Guess Number Higher or Lower II | Interval DP / Minimax Interval DP | url | |
| 357. Count Numbers with Unique Digits | brute foece | url | |
| 343. Integer Break | dp/dp[i] = the maximum product that can be obtained by breaking integer i into smaller | url | |
| 337. House Robber III | tree dp/ rob,not rob | url | |
| 279. Perfect Squares | dp/the number of value to consist of the target number. | url | |
| 3043. Find the Length of the Longest Common Prefix | set()/brute force | url | |
| 313. Super Ugly Number | greedy | url | |
| 309. Best Time to Buy and Sell Stock with Cooldown | greedy | url | |
| 264. Ugly Number II | original/Triple pointer | url | |
| 241. Different Ways to Add Parentheses | dfs/defaultdict | url | |
| 213. House Robber II | dp (2 types of search) | url | |
| 131. Palindrome Partitioning | bitmask brute-force | url | |
| 122. Best Time to Buy and Sell Stock II | Greedy/buy,sell | url | |
| 97. Interleaving String | 2dimention, dp() | url | |
| 96. Unique Binary Search Trees | BST, dp() | url | |
| 2657. Find the Prefix Common Array of Two Arrays | defaultdict() | url | |
| 2540. Minimum Common Value | set() | url | |
| 1345. Jump Game IV | BFS/Set() | url | |
| 95. Unique Binary Search Trees II | Binary Tree / Recursive function | url | |
| 72. Edit Distance | Dynamic Programming (DP) in 2 dimensions / string | url | |
| 64. Minimum Path Sum | Dynamic Programming (DP) in 2 dimensions | url | |
| 63. Unique Paths II | Dynamic Programming (DP) in 2 dimensions | url | |
| 45. Jump Game II | dp | url | |
| 1306. Jump Game III | Breadth-First Search (BFS) | url | |
| 154. Find Minimum in Rotated Sorted Array II | binary search + duplicate/worst case O(n) | url | |
| 1665. Minimum Initial Energy to Finish Tasks | Sort the tasks in order of higher starting requirements but lower energy consumption. | url | |
| 1674. Minimum Moves to Make Array Complementary | differencial array | url | |
| 153. Find Minimum in Rotated Sorted Array | binary search | url | |
| 2784. Check if Array is Good | for / if | url | |
| 2553. Separate the Digits in an Array | Convert an integer to a string | url | |
| 1025. Divisor Game | practice dp / If opponent loses at dp[i-x], current player can force a win | url | |
| 1668. Maximum Repeating Substring | practice dp | url | |
| 1137. N-th Tribonacci Number | practice dp | url | |
| 746. Min Cost Climbing Stairs | practice dp | url | |
| 509. Fibonacci Number | practice dp | url | |
| 392. Is Subsequence | practice dp | url | |
| 338. Counting Bits | practice dp | url | |
| 121. Best Time to Buy and Sell Stock | practice dp | url | |
| 119. Pascal's Triangle II | practice dp | url | |
| 70. Climbing Stairs | practice dp | url | |
| 1914. Cyclically Rotating a Grid | BruteForce | url | |
| 3629. Minimum Jumps to Reach End via Prime Teleportation | Prime/BFS | url | |
| 3660. Jump Game IX | Prefix Maximum/suffix minimum | url | |
| 1861. Rotating the Box | Right-->Left Greedy, algorithm/two-pointer simulation | url | |
| 796. Rotate String | Doubling | url | |
| 1722. Minimize Hamming Distance After Swap Operations | Union Find / Counter | url | |
| 2452. Words Within Two Edits of Dictionary | brute force / simulation / string comparison | url | |
| 2615. Sum of Distances | Manage the difference | url | |
| 788. Rotated Digits | Brute force/Greedy | url | |
| 396. Rotate Function | state transition | url | |
| 3742. Maximum Path Score in a Grid | dp[j][i][cost]=score | url | |
| 2033. Minimum Operations to Make a Uni-Value Grid | median / mod | url | |
| 1391. Check if There is a Valid Path in a Grid | BFS/Directional Connection | url | |
| 1559. Detect Cycles in 2D Grid | BFS/Loop Detection | url | |
| 2833. Furthest Point From Origin | count | url | |
| 2078. Two Furthest Houses With Different Colors | for/abs | url | |
| 3225. Maximum Score From Grid Operations | Column Height DP + Prefix Sum + Prefix/Suffix Optimization ** | url | |
| 3464. Maximize the Distance Between Points on a Square | Linearization + Binary Search + Greedy Check + Circular Validation | url | |
| 1855. Maximum Distance Between a Pair of Values | double pointer | url | |
| 2463. Minimum Total Distance Traveled | DP:Dynamic Programming with ordered assignment (sequence DP) | url | |
| 3488. Closest Equal Element Queries | precalculation/bisect_left | url | |
| 3761. Minimum Absolute Distance Between Mirror Pairs | reverse/str[::-1]/dp | url | |
| 3783. Mirror Distance of an Integer | reverse/str[::-1] | url | |
| 2515. Shortest Distance to Target String in a Circular Array | doubling | url | |
| 1848. Minimum Distance to the Target Element | for/if | url | |
| 514. Freedom Trail | A shortest-path problem that minimizes the sum of rotation cost and future cost; define dp(i, cur) as the minimum number of steps to spell key[i:] when the ring’s index cur is aligned at 12:00. | url | |
| 1289. Minimum Falling Path Sum II | DP: prev[j]: the minimum path sum ending at column j up to the previous row; store min1 and min2 (the smallest and second smallest values). | url | |
| 1463. Cherry Pickup II | DP: 3D dynamic programming (DP) with memoization over two robot positions, dp(r, c1, c2) means: the maximum number of cherries collectable from row r onward, when robot 1 is at column c1 and robot 2 is at column c2. | url | |
| 446. Arithmetic Slices II - Subsequence | DP: Use DP with hash maps to count arithmetic subsequences by extending previous sequences with the same difference. | url | |
| 629. K Inverse Pairs Array | DP: Use prefix-sum optimized DP to count ways of forming exactly k inverse pairs by inserting each number into all possible positions. | url | |
| 1335. Minimum Difficulty of a Job Schedule | Interval DP that exhaustively tries all partition points, splitting from the front to minimize the maximum job difficulty of each day. | url | |
| 1531. String Compression II | DP:For each segment, it exhaustively compares all possibilities of forming it into a run while deleting the remaining characters.** | url | |
| 1269. Number of Ways to Stay in the Same Place After Some Steps** | DP: At each step, update the number of ways to stay at each index (pos), where dp[pos] represents the number of ways to be at position pos after the current number of steps.** | url | |
| 2742. Painting the Walls | DP: paying for wall i covers 1 + time[i] walls in total, so choose the cheapest set of paid walls. | url | |
| 1547. Minimum Cost to Cut a Stick | Interval DP: try every possible first cut and minimize total cost | url | |
| 1639. Number of Ways to Form a Target String Given a Dictionary | DP/A DP that builds the target from left to right using character frequencies per column | url | |
| 879. Profitable Schemes | DP/Knapsack | url | |
| 2218. Maximum Value of K Coins From Piles | DP/The last k songs are all distinct | url | |
| 920. Number of Music Playlists | DP/The last k songs are all distinct | url | |
| 874. Walking Robot Simulation | Step move/If/while | url | |
| 2069. Walking Robot Simulation II | Step move/If/while | url | |
| 3741. Minimum Distance Between Three Equal Elements II | Sliding window on grouped indices | url | |
| 3655. XOR After Range Multiplication Queries II | DP/Square root decomposition + residue class partitioning + multiplicative difference array | url | |
| 1866. Number of Ways to Rearrange Sticks With K Sticks Visible | DP/Split by the largest element (n) | url | |
| 1220. Count Vowels Permutation | DP/Strings count | url | |
| 1092. Shortest Common Supersequence | DP/lcs/recovery | url | |
| 552. Student Attendance Record II | DP/l*a state transition | url | |
| 689. Maximum Sum of 3 Non-Overlapping Subarrays | Precalculation | url | |
| 657. Robot Return to Origin | basic | url | |
| 1964. Find the Longest Valid Obstacle Course at Each Position | bisect/list.append()/DP | url | |
| 1964. Find the Longest Valid Obstacle Course at Each Position | DP/strictly increasing subsequence | url | |
| 1799. Maximize Score After N Operations | dfs/@lru_cache(None) | url | |
| 2075. Decode the Slanted Ciphertext | row/col | url | |
| 3661. Maximum Walls Destroyed by Robots | sort/DP(left->right,right->left,left->left,right->right) | url | |
| 3418. Maximum Amount of Money Robot Can Earn | DP/for | url | |
| 3474. Lexicographically Smallest Generated String | DP/KMP/greedy** | url | |
| 2751. Robot Collisions | DP/sort | url | |
| 2840. Check if Strings Can be Made Equal With Operations II | defaultdict | url | |
| 691. Stickers to Spell Word | DFS/lru_cache | url | |
| 2493. Divide Nodes Into the Maximum Number of Groups | BFS/Graph Traversal | url | |
| 3203. Find Minimum Diameter After Merging Two Trees | Tree, radius/radius | url | |
| 2045. Second Minimum Time to Reach Destination | Minimum/Second Minumum | url | |
| 1568. Minimum Number of Days to Disconnect Island | Graph/Connected | url | |
| 1579. Remove Max Number of Edges to Keep Graph Fully Traversable | UnionFind for 2 | url | |
| 2839. Check if Strings Can be Made Equal With Operations I | defaultdict | url | |
| 2127. Maximum Employees to Be Invited to a Meeting | Functional Graph/longest chain, cyclic detection | url | |
| 2421. Number of Good Paths | Unionfind | url | |
| 3108. Minimum Cost Walk in Weighted Graph | And/UnionFind(union,find)/list | url | |
| 827. Making A Large Island | BFS/Set | url | |
| 2577. Minimum Time to Visit a Cell In a Grid | Dijkstra/Mininum dist update | url | |
| 2573. Find the String with LCP | DP/LCP | url | |
| 3548. Equal Sum Grid Partition II | Defaultdict/Sum | url | |
| 2946. Matrix Similarity After Cyclic Shifts | shift | url | |
| 3546. Equal Sum Grid Partition I | sum() | url | |
| 2906. Construct Product Matrix | prefix/suffix | url | |
| 1594. Maximum Non Negative Product in a Matrix | dp(max,min) | url | |
| 1886. Determine Whether Matrix Can Be Obtained By Rotation | 90 Degree rotation | url | |
| 2050. Parallel Courses III | topological sort/dp | url | |
| 2092. Find All People With Secret | BFS/sort/set() | url | |
| 1553. Minimum Number of Days to Eat N Oranges | Memoized Recursion | url | |
| 1857. Largest Color Value in a Directed Graph | BFS/Topological sort/DP | url | |
| 3643. Flip Square Submatrix Vertically | Greedy | url | |
| 3567. Minimum Absolute Difference in Sliding Submatrix | set/sort | url | |
| 3212. Count Submatrices With Equal Frequency of X and Y | submatrices/Accumulated-Sum | url | |
| 3070. Count Submatrices with Top-Left Element and Sum Less Than k | Accumulated-Sum | url | |
| 1727. Largest Submatrix With Rearrangements | sort/Create a histogram using each row as the base, then rearrange the columns to find the largest rectangle. | url | |
| 773. Sliding Puzzle | Brute Force/All state search/BFS | url | |
| 2872. Maximum Number of K-Divisible Components | BFS from EdgeNote | url | |
| 1622. Fancy Sequence | Lazy Linear Transformation/segment tree lazy propagation/inverse | url | |
| 1878. Get Biggest Three Rhombus Sums in a Grid | Brute Force/Greedy | url | |
| 1415. The k-th Lexicographical String of All Happy Strings of Length n | Recursive/reverse/k-th | url | |
| 149. Max Points on a Line | Slope / Slope normalization / Reduced fraction / Greatest common divisor | url | |
| 273. Integer to English Words | Recursive/Helper function | url | |
| 1611. Minimum One Bit Operations to Make Integers Zero | Bit Operation/Recursive Process | url | |
| 3600. Maximize Spanning Tree Stability with Upgrades | binary search/union find/Spanning Tree | url | |
| 3130. Find All Possible Stable Binary Arrays II | dynamic programming | url | |
| 3296. Minimum Number of Seconds to Make Mountain Height Zero | Binary Search/quadratic formula | url | |
| 1009. Complement of Base 10 Integer | bit flip/reverse,join(),map(str,l),int(x,2) | url | |
| 352. Data Stream as Disjoint Intervals | count numerical continuous length | url | |
| 1980. Find Unique Binary String | Brute force | url | |
| 2818. Apply Operations to Maximize Score | greedy/Count candidate and greedy | url | |
| 3068. Find the Maximum Sum of Node Values | greedy/xor | url | |
| 1793. Maximum Score of a Good Subarray | greedy/left,right,expansion based on k | url | |
| 995. Minimum Number of K Consecutive Bit Flips | greedy | url | |
| 1368. Minimum Cost to Make at Least One Valid Path in a Grid | 0-1 BFS | url | |
| 2503. Maximum Number of Points From Grid Queries | Heap/BFS | url | |
| 3045. Count Prefix and Suffix Pairs II | Tri-Tree,border/KMP/Trie** | url | |
| 1255. Maximum Score Words Formed by Letters | backtracking/Bitmask Enumeration/Counter | url | |
| 1888. Minimum Number of Flips to Make the Binary String Alternating | rotate string/String Doubling | url | |
| 1784. Check if Binary String Has at Most One Segment of Ones | Count Continuous Sequences | url | |
| 1758. Minimum Changes To Make Alternating Binary String | compare binary strings | url | |
| 1582. Special Positions in a Binary Matrix | Matrix Search | url | |
| 1545. Find Kth Bit in Nth Binary String | Recursive Search | url | |
| 1536. Minimum Swaps to Arrange a Binary Grid | swap/greedy inseartion sort | url | |
| 1689. Partitioning Into Minimum Number Of Deci-Binary Numbers | int()/max() | url | |
| 3666. Minimum Operations to Equalize Binary String Solved | heuristic count | url | |
| 1680. Concatenation of Consecutive Binary Numbers | bit operation | url | |
| 1404. Number of Steps to Reduce a Number in Binary Representation to One | int(s,2)/divide,mod | url | |
| 1 Bits | sort/tuple() | url | |
| 1022. Sum of Root To Leaf Binary Numbers | dfs/binary operation | url | |
| 1461. Check If a String Contains All Binary Codes of Size K | Sliding Window | url | |
| 868. Binary Gap | Binary translation / max() | url | |
| 761. Special Binary String | Divide and Conquer / Recursion / Greedy Algorithm | url | |
| 762. Prime Number of Set Bits in Binary Representation | Bit Operation | url | |
| 696. Count Binary Substrings | Count number | url | |
| 693. Binary Number with Alternating Bits | Bit Operation | url | |
| 401. Binary Watch | Bit Operation, BruteForce, bin(h) transfer | url | |
| 190. Reverse Bits | Bit Operation/Divide,Remainder/Modulus | url | |
| 67. Add Binary | While/i,j,iterator/carry | url | |
| 3714. Longest Balanced Substring II | Prefix Sum / Cumulative Difference / State Matching | url | |
| 799. Champagne Tower | Simulate all cases | url | |
| 3713. Longest Balanced Substring I | Constraint-based Search | url | |
| 3721. Longest Balanced Subarray II | Segment Tree | url | |
| 3719. Longest Balanced Subarray I | Brute force | url | |
| 686. Repeated String Match | Boyer–Moore/Pattern Matching | url | |
| 1044. Longest Duplicate Substring | Rabin-Karp/Rolling Hash | url | |
| 28. Find the Index of the First Occurrence in a String | String Compare | url | |
| 1382. Balance a Binary Search Tree | Balance a Binary Search Tree/Recursive Tree Construction | url | |
| 110. Balanced Binary Tree | Recursive | url | |
| 719. Find K-th Smallest Pair Distance | Binary Search / Sliding Window | url | |
| 726. Number of Atoms | Stack / Hierarchical deque structure | url | |
| 1106. Parsing A Boolean Expression | Stack-based nested expression parsing from ")". | url | |
| 862. Shortest Subarray with Sum at Least K | Prefix Sum / Deque | url | |
| 2751. Robot Collisions | Stack/O(n) | url | |
| 632. Smallest Range Covering Elements from K Lists | Sliding Window/count unique_lists_in_window | url | |
| 2009. Minimum Number of Operations to Make Array Continuous | Sord/Sliding Windows | url | |
| 2306. Naming a Company | Set Difference of First Letters / Counting Duplicates | url | |
| 1074. Number of Submatrices That Sum to Target | Accumulated Sum | url | |
| 214. Shortest Palindrome | KMP法（Knuth-Morris-Pratt Algorithm） Table | url | |
| 1653. Minimum Deletions to Make String Balanced | Dynamic Programming | url | |
| 3634. Minimum Removals to Balance Array | Binary Search | url | |
| 3379. Transformed Array | Index Control. | url | |
| 3640. Trionic Array II | DP(Use the cumulative sums of increasing and decreasing sequences as DP states.) | url | |
| 3637. Trionic Array I | Brute Force | url | |
| 3013. Divide an Array Into Subarrays With Minimum Cost II | Sliding Window K-Minimum Sum/SortedList() | url | |
| 407. Trapping Rain Water II | Heap/BFS | url | |
| 2290. Minimum Obstacle Removal to Reach Corner | 0-1BFS | url | |
| 3010. Divide an Array Into Subarrays With Minimum Cost I | sort | url | |
| 2977. Minimum Cost to Convert String II | Graph/Dijkstra/Tri-Tree/DP | url | |
| 2976. Minimum Cost to Convert String I | Floyd-Warshall | url | |
| 744. Find Smallest Letter Greater Than Target | for/if | url | |
| 3651. Minimum Cost Path with Teleportations | Dynamic Programming with monotone teleportation updates/not dijkstra's algorithm | url | |
| 3650. Minimum Cost Path with Edge Reversals | dijkstra's algorithm | url | |
| 1200. Minimum Absolute Difference | sort/min | url | |
| 1984. Minimum Difference Between Highest and Lowest of K Scores | sort | url | |
| 1877. Minimize Maximum Pair Sum in Array | Greedy Search/Sort | url | |
| 3510. Minimum Pair Removal to Sort Array II | Greedy Algorithm/Min-Priority Queue/Doubly Linked List/Two Pointers Technique** | url | |
| 3507. Minimum Pair Removal to Sort Array I | Lazy Update in Heap | url | |
| 3315. Construct the Minimum Bitwise Array II | Bit calculation | url | |
| 3314. Construct the Minimum Bitwise Array I | Bit calculation | url | |
| 1292. Maximum Side Length of a Square with Sum Less than or Equal to Threshold | Greedy/Monotonic Improvement, 2D Prefix Sum | url | |
| 1895. Largest Magic Square | Accumlated Sum/Brute force | url | |
| 3454. Separate Squares II Solved | Segment Tree** | url | |
| 3047. Find the Largest Area of Square Inside Two Rectangles | Greedy/Combinations | url | |
| 2975. Maximum Square Area by Removing Fences From a Field | Greedy/Combinations | url | |
| 2943. Maximize Area of Square Hole in Grid | Greedy | url | |
| 3453. Separate Squares I | Binary Search | url | |
| 1266. Minimum Time Visiting All Points | the Chebyshev distances | url | |
| 85. Maximal Rectangle | Calculating the 'Maximum Expansion' for each cell. | url | |
| 1458. Max Dot Product of Two Subsequences | DP/SubSequences | url | |
| 712. Minimum ASCII Delete Sum for Two Strings | DP/2dimentions | url | |
| 865. Smallest Subtree with all the Deepest Nodes | DFS/Depth Search | url | |
| 1339. Maximum Product of Splitted Binary Tree | Total - SubTree | url | |
| 1161. Maximum Level Sum of a Binary Tree | Broaden First Search | url | |
| 1975. Maximum Matrix Sum | Brute Force | url | |
| 1390. Four Divisors | Sieve of Eratosthenes | url | |
| 1970. Last Day Where You Can Still Cross | binary search/bfs | url | |
| 961. N-Repeated Element in Size 2N Array | set/defaultdict | url | |
| 66. Plus One | for/digit/add | url | |
| 840. Magic Squares In Grid | Brute Force | url | |
| 756. Pyramid Transition Matrix | DFS/BFS | url | |
| 1351. Count Negative Numbers in a Sorted Matrix | for | url | |
| 2483. Minimum Penalty for a Shop | brute force | url | |
| 3075. Maximize Happiness of Selected Children | sort/for | url | |
| 3074. Apple Redistribution into Boxes | sort | url | |
| 2054. Two Best Non-Overlapping Events | Sort/Binary Search | url | |
| 955. Delete Columns to Make Sorted II | compare the orger of strings | url | |
| 3652. Best Time to Buy and Sell Stock using Strategy | sliding window(manage positive,negative) | url | |
| 944. Delete Columns to Make Sorted | row/col | url | |
| 3573. Best Time to Buy and Sell Stock V | Dynamic Programming | url | |
| 2110. Number of Smooth Descent Periods of a Stock | Dynamic Programming | url | |
| 227. Basic Calculator II | Basic Operation / plug translation | url | |
| 153. Find Minimum in Rotated Sorted Array | binary search | url | |
| 61. Rotate List | List, Head/Tail | url | |
| 16. 3Sum Closest | Double Pointer algorithm | url | |
| 863. All Nodes Distance K in Binary Tree | adjacent list/bfs | url | |
| 787. Cheapest Flights Within K Stops | djkstra algorithm | url | |
| 73. Set Matrix Zeroes | matrix processing | url | |
| 7. Reverse Integer | reverse | url | |
| 91. Decode Ways | Dynamic Programming | url | |
| 179. Largest Number | compare_func, custom sort | url | |
| 74. Search a 2D Matrix | binary search | url | |
| 50. Pow(x, n) | Binary Exponentiation | url | |
| 437. Path Sum III | DFS/prefix_sum | url | |
| 143. Reorder List | reverse | url | |
| 103. Binary Tree Zigzag Level Order Traversal | Binary Tree | url | |
| 48. Rotate Image | rotate | url | |
| 221. Maximal Square | dynamic programming | url | |
| 215. Kth Largest Element in an Array | heapreplace, heappop()/heappush() | url | |
| 528. Random Pick with Weight | rand() | url | |
| 735. Asteroid Collision | stack, pop/append | url | |
| 3433. Count Mentions Per User | Message Data Processing | url | |
| 3606. Coupon Code Validator | isalnum | url | |
| 3531. Count Covered Buildings | Check each maximum building blocks | url | |
| 3577. Count the Number of Computer Unlocking Permutations | Check the problen condition carefully | url | |
| 3583. Count Special Triplets | Counter/Counting from the middle | url | |
| 435. Non-overlapping Intervals | sort/brute force | url | |
| 380. Insert Delete GetRandom O(1) | insert/delete/hashmap | url | |
| 377. Combination Sum IV | Dynamic Programming | url | |
| 560. Subarray Sum Equals K | accumlated sums/defaultdict | url | |
| 1925. Count Square Sum Triples | Count Sum Triples | url | |
| 148. Sort List | merge sort | url | |
| 22. Generate Parentheses | BFS | url | |
| 662. Maximum Width of Binary Tree | binary tree/calculate index on TreeNode | url | |
| 658. Find K Closest Elements | Binary search/Sliding window | url | |
| 424. Longest Repeating Character Replacement | Sliding window search | url | |
| 55. Jump Game | Greedy | url | |
| 300. Longest Increasing Subsequence | bisect()/optimization | url | |
| 210. Course Schedule II | toporogical Sort/BFS | url | |
| 24. Swap Nodes in Pairs | 2 pointer | url | |
| 113. Path Sum II | BFS/DFS | url | |
| 128. Longest Consecutive Sequence | hash set | url | |
| 189. Rotate Array | reverse | url | |
| 328. Odd Even Linked List | Pointer | url | |
| 394. Decode String | encode/decode/stack | url | |
| 525. Contiguous Array | window search/memory left side | url | |
| 1523. Count Odd Numbers in an Interval Range | Odd | url | |
| 3578. Count Partitions With Max-Min Difference at Most K | DP/Sliding window | url | |
| 3432. Count Partitions with Even Sum Difference | Count/Brute Force | url | |
| 2211. Count Collisions on a Road | Simplify the problem | url | |
| 3623. Count Number of Trapezoids I | the number of horizontal trapezoids/sum | url | |
| 1590. Make Sum Divisible by P | mod/subarray | url | |
| 230. Kth Smallest Element in a BST | binary tree | url | |
| 739. Daily Temperatures | monotonic stack | url | |
| 198. House Robber | Dynamic Programming | url | |
| 134. Gas Station | greedy | url | |
| 31. Next Permutation | Find next permutation | url | |
| 36. Valid Sudoku | set/for | url | |
| 49. Group Anagrams | dictionaly/set/append | url | |
| 152. Maximum Product Subarray | Dynamic Programming/keep both max and min valude. | url | |
| 211. Design Add and Search Words Data Structure | Trie Tree/Data structure for String Search | url | |
| 417. Pacific Atlantic Water Flow | set.intersection()/bfs | url | |
| 287. Find the Duplicate Number | binary search | url | |
| 19. Remove Nth Node From End of List | LinkedList | url | |
| 692. Top K Frequent Words | Counter/Heap | url | |
| 146. LRU Cache | HashList/Queue | url | |
| 621. Task Scheduler | Greedy Algorithm | url | |
| 310. Minimum Height Trees | Tree/Extract leave | url | |
| 438. Find All Anagrams in a String | Window Search | url | |
| 79. Word Search | dfs | url | |
| 17. Letter Combinations of a Phone Number | Combination/BFS,DFS | url | |
| 11. Container With Most Water | Two pointer approach | url | |
| 3381. Maximum Subarray Sum With Length Divisible by K | dynamic programming | url | |
| 76. Minimum Window Substring | two pointer approach | url | |
| 297. Serialize and Deserialize Binary Tree | serialize/deserialize | url | |
| 42. Trapping Rain Water | pre-calculation | url | |
| 295. Find Median from Data Stream | heap/control two heap | url | |
| 127. Word Ladder | bfs, word distance | url | |
| 224. Basic Calculator | stack/while/calculation | url | |
| 105. Construct Binary Tree from Preorder and Inorder Traversal | - | url | |
| 62. Unique Paths | dynamic programming/bfs | url | |
| 199. Binary Tree Right Side View | bfs, binary tree | url | |
| 78. Subsets | bfs, list | url | |
| 54. Spiral Matrix | matrix control | url | |
| 8. String to Integer (atoi) | atoi | url | |
| 416. Partition Equal Subset Sum | dynamic programming | url | |
| 139. Word Break | dynamic programming | url | |
| 757. Set Intersection Size At Least Two | greedy | url | |
| 2435. Paths in Matrix Whose Sum Is Divisible by K | dynamic programming | url | |
| 1015. Smallest Integer Divisible by K | Repunit Number | url | |
| 1018. Binary Prefix Divisible By 5 | binary, bit operation | url | |
| 1262. Greatest Sum Divisible by Three | dynamic programming | url | |
| 3190. Find Minimum Operations to Make All Elements Divisible by Three | mod 3 | url | |
| 1930. Unique Length-3 Palindromic Subsequences | set/greedy search | url | |
| 2154. Keep Multiplying Found Values by Two Solved | while | url | |
| 717. 1-bit and 2-bit Characters | flag | url | |
| 1437. Check If All 1's Are at Least Length K Places Away | count the number of zeros. | url | |
| 1513. Number of Substrings With Only 1s | count the number of coutinuous ones. | url | |
| 1235. Maximum Profit in Job Scheduling | binary search/ | url | |
| 23. Merge k Sorted Lists | priority queue | url | |
| 84. Largest Rectangle in Histogram | Height management/dynamic programming | url | |
| 124. Binary Tree Maximum Path Sum Solved | Recursive DFS | url | |
| 895. Maximum Frequency Stack | stack/defaultdict(manage frequency of the numbers.) | url | |
| 39. Combination Sum | BFS/backtrack/DP | url | |
| 33. Search in Rotated Sorted Array | binary-search | url | |
| 46. Permutations | backtracking | url | |
| 56. Merge Intervals | list | url | |
| 236. Lowest Common Ancestor of a Binary Tree | Lowest Common Ancestor | url | |
| 981. Time Based Key-Value Store | set()/list | url | |
| 75. Sort Colors | sort() | url | |
| 2536. Increment Submatrices by One | 2D Difference Array | url | |
| 3228. Maximum Number of Operations to Move Ones to the End | Dynamic Programming | url | |
| 3234. Count the Number of Substrings With Dominant Ones | pre-processing/calc 0(1) | url | |
| 2654. Minimum Number of Operations to Make All Array Elements Equal to 1 | GCD | url | |
| 994. Rotting Oranges | Broden First Search | url | |
| 200. Number of Islands | Union-Find | url | |
| 98. Validate Binary Search Tree | Node, Class | url | |
| 155. Min Stack | manage the current/current minumum value | url | |
| 238. Product of Array Except Self | product calculations | url | |
| 322. Coin Change | dynamic programming | url | |
| 208. Implement Trie (Prefix Tree) | Class/Tree | url | |
| 207. Course Schedule | Topological Sorting | url | |
| 474. Ones and Zeroes | knapsack problem | url | |
| 150. Evaluate Reverse Polish Notation | Reverse Polish Notation (RPN) | url | |
| 133. Clone Graph | graph/broden first search | url | |
| 102. Binary Tree Level Order Traversal | list/broden first search | url | |
| 15. 3Sum | 2 pointer | url | |
| 973. K Closest Points to Origin | sort/square | url | |
| 542. 01 Matrix | broden first search | url | |
| 57. Insert Interval | while/range | url | |
| 53. Maximum Subarray | kanade-algorithm,dynamic programming | url | |
| 12. Integer to Roman | while/divide/''.join(result) | url | |
| 8. String to Integer (atoi) | atoi/while/pre-processing | url | |
| 7. Reverse Integer | reverse number | url | |
| 6. Zigzag Conversion | zigzag/list/index control | url | |
| 5. Longest Palindromic Substring | expand_around_center | url | |
| 3. Longest Substring Without Repeating Characters | window search | url | |
| 2. Add Two Numbers | listNode/Linkedlist/class | url | |
| 3542. Minimum Operations to Convert All Elements to Zero | Monotonic stack | url | |
| 2169. Count Operations to Obtain Zero | substruction | url | |
| 3321. Find X-Sum of All K-Long Subarrays II | defaultdict/window search/sortedlist | url | |
| 2528. Maximize the Minimum Powered City | Window search/binary search/diff matrix | url | |
| 1611. Minimum One Bit Operations to Make Integers Zero | minimumOneBitOperations/GrayCode | url | |
| 3607. Power Grid Maintenance | union-find/sorted list(sortedlist.add(),sortedlist.remove(),sortedlist[0]) | url | |
| 3318. Find X-Sum of All K-Long Subarrays I | brute force | url | |
| 1578. Minimum Time to Make Rope Colorful | brute force | url | |
| 1526. Minimum Number of Increments on Subarrays to Form a Target Array | focus on diff | url | |
| 2257. Count Unguarded Cells in the Grid | broden first search | url | |
| 3217. Delete Nodes From Linked List Present in Array | linked list | url | |
| 3289. The Two Sneaky Numbers of Digitville | set | url | |
| 3370. Smallest Number With All Set Bits | n.bit_length() | url | |
| 3354. Make Array Elements Equal to Zero | simulate | url | |
| 2125. Number of Laser Beams in a Bank | list | url | |
| 2043. Simple Bank System | class/error check | url | |
| 2048. Next Greater Numerically Balanced Number | brute force | url | |
| 3461. Check If Digits Are Equal in String After Operations I | sum/mod | url | |
| 3346. Maximum Frequency of an Element After Performing Operations I | sort/binary search | url | |
| 2011. Final Value of Variable After Performing Operations | pattern match | url | |
| 1625. Lexicographically Smallest String After Applying Operations | brute force/BFS | url | |
| 3397. Maximum Number of Distinct Elements After Operations | sort/min/max | url | |
| 2598. Smallest Missing Non-negative Integer After Operations | mex/modulo operation | url | |
| 3350. Adjacent Increasing Subarrays Detection II | pre-calculate | url | |
| 3349. Adjacent Increasing Subarrays Detection I | list/for | url | |
| 2273. Find Resultant Array After Removing Anagrams | set()/string() | url | |
| 3186. Maximum Total Damage With Spell Casting | dynamic programming | url | |
| 3147. Taking Maximum Energy From the Mystic Dungeon | dynamic programming/reverse way | url | |
| 3494. Find the Minimum Amount of Time to Brew Potions | accumulated sum/simulate,calculate the earliest start time. | url | |
| 2300. Successful Pairs of Spells and Potions | bisect | url | |
| 1488. Avoid Flood in The City | bisect/list/set/brute force | url | |
| 778. Swim in Rising Water | Modified Dijkstra's Algorithm | url | |
| 11. Container With Most Water | two pointer approach (Greedy Two Pointers Algorithm) | url | |
| 3100. Water Bottles II | caluculate division/while | url | |
| 1518. Water Bottles | caluculate division | url | |
| 2221. Find Triangular Sum of an Array | dynamic programming | url | |
| 1039. Minimum Score Triangulation of Polygon | Interval Dynamic Programming | url | |
| 976. Largest Perimeter Triangle | Perimeter of Triangle | url | |
| 812. Largest Triangle Area | brute force/area of triangle(Surveyor's Formula) | url | |
| 611. Valid Triangle Number | sort/brute force search | url | |
| 120. Triangle | DP (The bottom-up approach) | url | |
| 166. Fraction to Recurring Decimal/long division | - | url | |
| 165. Compare Version Numbers | char.split()/int() | url | |
| 3005. Count Elements With Maximum Frequency | defaultdict | url | |
| 1912. Design Movie Rental System | heap()/sort()/defaultdict(list) | url | |
| 3508. Implement Router | defaultdict(list)/binary_search() | url | |
| 3484. Design Spreadsheet | dict()/string.sprit() | url | |
| 3408. Design Task Manager | heap() | url | |
| 2197. Replace Non-Coprime Numbers in Array | heap()/latest value management | url | |
| 1935. Maximum Number of Words You Can Type | set()/charactor | url | |
| 966. Vowel Spellchecker | pattern matching | url | |
| 3227. Vowels Game in a String | greedy | url | |
| 2785. Sort Vowels in a String | vowels/consonent/sort | url | |
| 1733. Minimum Number of People to Teach | set/min/greedy or brute force approach | url | |
| 3541. Find Most Frequent Vowel and Consonant | set | url | |
| 2327. Number of People Aware of a Secret | dp | url | |
| 1317. Convert Integer to the Sum of Two No-Zero Integers | for/brute force | url | |
| 1304. Find N Unique Integers Sum up to Zero | for | url | |
| 3495. Minimum Operations to Make Array Elements Zero | min | url | |
| 2749. Minimum Operations to Make the Integer Zero | bit operation/formulate | url | |
| 3516. Find Closest Person | absolute value | url | |
| 3027. Find the Number of Ways to Place People II | sort[x Ascending order,y Descending order]/ | url | |
| 3025. Find the Number of Ways to Place People I | brute force/for | url | |
| 1792. Maximum Average Pass Ratio | heap/calculate future gain | url | |
| 37. Sudoku Solver | recursive serarch | url | |
| 36. Valid Sudoku | set() | url | |
| 3021. Alice and Bob Playing Flower Game | odd/even | url | |
| 498. Diagonal Traverse | control index in 2d field | url | |
| 1493. Longest Subarray of 1's After Deleting One Element | window search | url | |
| 3195. Find the Minimum Area to Cover All Ones I | max/min, row/height | url | |
| 1504. Count Submatrices With All Ones | url | ||
| 1277. Count Square Submatrices with All Ones | DP for the number of areas | url | |
| 2348. Number of Zero-Filled Subarrays | calculate the contiguous sequence of elements | url | |
| 3000. Maximum Area of Longest Diagonal Rectangle | calculate the area/diagonal | url | |
| 679. 24 Game | Brute force/Recursive search | url | |
| 837. New 21 Game | Dynamic Programming/Probability/window sum | url | |
| 342. Power of Four | devided by three | url | |
| 2264. Largest 3-Same-Digit Number in String | for/maximum string | url | |
| 326. Power of Three | devided by three | url | |
| 2787. Ways to Express an Integer as Sum of Powers | Dynamic Programming | url | |
| 2438. Range Product Queries of Powers | Prefix Product Preprocessing/modular inverses | url | |
| 869. Reordered Power of 2 | counter | url | |
| 231. Power of Two | n&(n-1)=0 | url | |
| 1323. Maximum 69 Number | string.replace("6","9",1) | url | |
| 808. Soup Servings | dp/probability | url | |
| 898. Bitwise ORs of Subarrays | Dynamic Programming, Monotonic increasing | url | |
| 118. Pascal's Triangle | for/if | url | |
| 904. Fruit Into Baskets | sliding window | url | |
| 3477. Fruits Into Baskets II | brute force search | url | |
| 3479. Fruits Into Baskets III | segment tree/Efficient range maximum,minimum query under 'left-to-right' constraint | url | |
| 2419. Longest Subarray With Maximum Bitwise AND | Greedy search | url | |
| 2411. Smallest Subarrays With Maximum Bitwise OR | Bit Manipulation / Greedy Algorithm / Reverse Iteration / Bit Tracking | url | |
| 2044. Count Number of Maximum Bitwise-OR Subsets | brute-force search with bit manipulation | url | |
| 2210. Count Hills and Valleys in an Array | for/if | url | |
| 1717. Maximum Score From Removing Substrings | greedy approach | url | |
| 1695. Maximum Erasure Value | sliding window approach | url | |
| 1957. Delete Characters to Make Fancy String | if/len | url | |
| 1233. Remove Sub-Folders from the Filesystem | sort/startwith() | url | |
| 3202. Find the Maximum Length of Valid Subsequence II | dp(mod k) | url | |
| 3201. Find the Maximum Length of Valid Subsequence I | brute force(odd+odd/even+even/odd+even/even+odd) | url | |
| 3487. Maximum Unique Subarray Sum After Deletion | sliding window/set | url | |
| 3136. Valid Word | set/if/for/isdigit()/isalpha() | url | |
| 1290. Convert Binary Number in a Linked List to Integer | list/bit length | url | |
| 2410. Maximum Matching of Players With Trainers | greedy/sort | url | |
| 3440. Reschedule Meetings for Maximum Free Time II | accumulated sum/window search | url | |
| 3439. Reschedule Meetings for Maximum Free Time I | accumulated sum/window search | url | |
| 1353. Maximum Number of Events That Can Be Attended | Heap/Greedy Algorithm | url | |
| 1865. Finding Pairs With a Certain Sum | freq/defaultdict | url | |
| 3579. Minimum Steps to Convert String with Operations | DynamicProgramming/Substring partitioning with recursive optimization of reverse, swap, and replace operations | url | |
| 3597. Partition String | set/string | url | |
| 1394. Find Lucky Integer in an Array | defaultdict | url | |
| 3602. Hexadecimal and Hexatrigesimal Conversion | base16 | url | |
| 3333. Find the Original Typed String II | Dynamic Programming/after-effects/cumulative sum | url | |
| 3304. Find the K-th Character in String Game I | while | url | |
| 3330. Find the Original Typed String I | array | url | |
| 594. Longest Harmonious Subsequence | array | url | |
| 1498. Number of Subsequences That Satisfy the Given Sum Condition | Double Pointer Sliding Window | url | |
| 2014. Longest Subsequence Repeated k Times | iterator/BFS | url | |
| 2040. Kth Smallest Product of Two Sorted Arrays | binary search/Divide and Conquer | url | |
| 2081. Sum of k-Mirror Numbers | palindrome/base-k/yeild | url | |
| 2099. Find Subsequence of Length K With the Largest Sum | brute force | url | |
| 2311. Longest Binary Subsequence Less Than or Equal to K | brute force | url | |
| 2200. Find All K-Distant Indices in an Array | for/if/array | url | |
| 2138. Divide a String Into Groups of Size k | brute force | url | |
| 3085. Minimum Deletions to Make String K-Special | brute force for all candidates | url | |
| 3443. Maximum Manhattan Distance After K Changes | step-by-step/count the maximum distance in each step by O(1) | url | |
| 2294. Partition Array Such That Maximum Difference Is K | sort/brute force | url | |
| 2966. Divide Array Into Arrays With Max Difference | sort/brute force | url | |
| 2016. Maximum Difference Between Increasing Elements | diff/brute force | url | |
| 1432. Max Difference You Can Get From Changing an Integer | replace integer/str.replace(s1,s2) | url | |
| 2616. Minimize the Maximum Difference of Pairs | binary search | url | |
| 2566. Maximum Difference by Remapping a Digit | replace | url | |
| 3423. Maximum Difference Between Adjacent Elements in a Circular Array | index of Adjacent Elements | url | |
| 3442. Maximum Difference Between Even and Odd Frequency I | odd/even | url | |
| 386. Lexicographical Numbers | increment Lexicographically | url | |
| 1298. Maximum Candies You Can Get from Boxes | BFS(Broaden firsts search) | url | |
| 3170. Lexicographically Minimum String After Removing Stars | stack push(),pop() | url | |
| 2434. Using a Robot to Print the Lexicographically Smallest String | stack/manage minimum charactor string | url | |
| 1061. Lexicographically Smallest Equivalent String | UnionFind | url | |
| 3403. Find the Lexicographically Largest String From the Box I | Lexicographically Large/Start from lerge char string | url | |
| 135. Candy | Greedy Algorithm/Bidirectional Scan/Local Optimization | url | |
| 2929. Distribute Candies Among Children II | inclusion-exclusion principle | url | |
| 909. Snakes and Ladders | BFS | url | |
| 2359. Find Closest Node to Given Two Nodes | BFS | url | |
| 3373. Maximize the Number of Target Nodes After Connecting Trees II | BFS/binary tree capability,structure | url | |
| 3372. Maximize the Number of Target Nodes After Connecting Trees I | BFS/Tree structure | url | |
| 2894. Divisible and Non-divisible Sums Difference | for/number sequence | url | |
| 1857. Largest Color Value in a Directed Graph | topological sort/dp | url | |
| 3068. Find the Maximum Sum of Node Values | pick up gain from sorted array | url | |
| 3068. Find the Maximum Sum of Node Values | fascinating key insight | url | |
| 2131. Longest Palindrome by Concatenating Two Letter Words | count reversed words/pair words | url | |
| 2942. Find Words Containing Character | if/array/enumerate | url | |
| 3362. Zero Array Transformation III | sort/heapq/differencial sum | url | |
| 73. Set Matrix Zeroes | in-place zero flag | url | |
| 3355. Zero Array Transformation I | Difference Array(imos) | url | |
| 3024. Type of Triangle | if/array/sort | url | |
| 1931. Painting a Grid With Three Different Colors | DP/check state transition | url | |
| 3337. Total Characters in String After Transformations II | Approach: Matrix Multiplication + Matrix Exponentiation By Squaring | url | |
| 75. Sort Colors | sort | url | |
| Longest Unequal Adjacent Groups Subsequence II | dynamic programming | url | |
| 2900. Longest Unequal Adjacent Groups Subsequence I | count | url | |
| 3335. Total Characters in String After Transformations I | counter/26characters | url | |
| 2094. Finding 3-Digit Even Numbers | brute force | url | |
| 1550. Three Consecutive Odds | odd/even | url | |
| 3343. Count Number of Balanced Permutations | dynamic programming/combinations | url | |
| 2918. Minimum Equal Sum of Two Arrays After Replacing Zeros | case division | url | |
| 3342. Find Minimum Time to Reach Last Room II | heapq/djkstra algorithm | url | |
| 3341. Find Minimum Time to Reach Last Room I | Shortest Path + Dijkstra | url | |
| 1920. Build Array from Permutation | array/for | url | |
| 790. Domino and Tromino Tiling | Dynamic Programming | url | |
| 2071. Maximum Number of Tasks You Can Assign | binary search/sort | url | |
| 1128. Number of Equivalent Domino Pairs | defaultdict/combination | url | |
| 1007. Minimum Domino Rotations For Equal Row | Brute force | url | |
| 838. Push Dominoes | Brute force | url | |
| 1295. Find Numbers with Even Number of Digits | odd/even | url | |
| 2962. Count Subarrays Where Max Element Appears at Least K Times | sliding window | url | |
| 2302. Count Subarrays With Score Less Than K | sliding window | url | |
| 3392. Count Subarrays of Length Three With a Condition | sum | url | |
| 2845. Count of Interesting Subarrays | accumlated sum | url | |
| 2799. Count Complete Subarrays in an Array | sliding window | url | |
| 1399. Count Largest Group | defaultdict,str(),int(),max | url | |
| 2145. Count the Hidden Sequences | min/max/array | url | |
| 2179. Count Good Triplets in an Array | Binary Indexed Tree/Count left and right previously/index alignment | url | |
| 1922. Count Good Numbers | pattern/count | url | |
| 1534. Count Good Triplets | brute force approach | url | |
| 2537. Count the Number of Good Subarrays | sliding window/count pairs | url | |
| 2176. Count Equal and Divisible Pairs in an Array | brute force approach | url | |
| 38. Count and Say | Recursive/run-length encoding | url | |
| 2563. Count the Number of Fair Pairs | binary search | url | |
| 781. Rabbits in Forest | patten/divide/mod | url | |
| 2843. Count Symmetric Integers | str/loop/while | url | |
| 3375. Minimum Operations to Make Array Values Equal to K | set | url | |
| 3396. Minimum Number of Operations to Make Elements in Array Distinct | defaultdict | url | |
| 416. Partition Equal Subset Sum | dynamic programing/partial sum | url | |
| 368. Largest Divisible Subset | dynamic programing/back trace | url | |
| 1863. Sum of All Subset XOR Totals | Full bit search algorithm | url | |
| 2140. Solving Questions With Brainpower | dynamic programming/update value and inherit the maximum value | url | |
| 2873. Maximum Value of an Ordered Triplet I | same as II | url | |
| 2874. Maximum Value of an Ordered Triplet II | cumulative sum/Greedy + Prefix Suffix Array | url | |
| 1123. Lowest Common Ancestor of Deepest Leaves | depth first search/binary tree | url | |
| 2780. Minimum Index of a Valid Split | accumulate/count from both left and right | url | |
| 763. Partition Labels | min/max | url | |
| 2033. Minimum Operations to Make a Uni-Value Grid | median/accumrated sum | url | |
| 3394. Check if Grid can be Cut into Sections | sort/blute force | url | |
| 3169. Count Days Without Meetings | line sweep/imos/defaultdict | url | |
| 2115. Find All Possible Recipes from Given Supplies | Tree/BFS from edges | url | |
| 2401. Longest Nice Subarray | sliding window | url | |
| 3191. Minimum Operations to Make Binary Array Elements Equal to One I | bit反転 | url | |
| 2685. Count the Number of Complete Components | BFS/count the number of vertex,edge | url | |
| 1976. Number of Ways to Arrive at Destination | Djikstra/ShortestPathLength | url | |
| 3108. Minimum Cost Walk in Weighted Graph | BFS/UnionTree/And(add 1 to all bits is "-1") | url | |
| 2206. Divide Array Into Equal Pairs | count odd | url | |
| 3356. Zero Array Transformation II | binary search | url | |
| 2594. Minimum Time to Repair Cars | binary search | url | |
| 2226. Maximum Candies Allocated to K Children | binary search | url | |
| 2529. Maximum Count of Positive Integer and Negative Integer | neg/pos count | url | |
| 1358. Number of Substrings Containing All Three Characters | 動的計画法 | url | |
| 2560. House Robber IV | 二分探索/全探索 | url | |
| 3306. Count of Substrings Containing Every Vowel and K Consonants II | sliding window | url | |
| 3208. Alternating Groups II | deque | url | |
| 2523. Closest Prime Numbers in Range | Sieve of Eratosthenes | url | |
| 2379. Minimum Recolors to Get K Consecutive Black Blocks | sliding window | url | |
| 1780. Check if Number is a Sum of Powers of Three | raising a number to a power | url | |
| 2579. Count Total Number of Colored Cells | calculate area | url | |
| 2965. Find Missing and Repeated Values | list | url | |
| 2161. Partition Array According to Given Pivot | array | url | |
| 2570. Merge Two 2D Arrays by Summing Values | sort/defaultdict | url | |
| 2460. Apply Operations to an Array | 愚直/BruteForce | url | |
| 873. Length of Longest Fibonacci Subsequence | フィボナッチ風数列/全探索/DP | url | |
| 1749. Maximum Absolute Sum of Any Subarray | 累積和のMin/Max | url | |
| 1524. Number of Sub-arrays With Odd Sum | DP/i番目までの偶奇の数 | url | |
| 2467. Most Profitable Path in a Tree | BFS/DFS | url | |
| 1028. Recover a Tree From Preorder Traversal | 二分木/TreeNode()/深さ計算してTree再現 | url | |
| 889. Construct Binary Tree from Preorder and Postorder Traversal | pre/postorderで探索indexを操作してTree再現 | url | |
| 1261. Find Elements in a Contaminated Binary Tree | binary tree/pointer/dfs | url | |
| 1980. Find Unique Binary String | 10進数への変換/文字列操作 | url | |
| 1415. The k-th Lexicographical String of All Happy Strings of Length n | 再帰/昇順に条件に合致する文字列を全探索して接続する/k番目を出力する | url | |
| 2375. Construct Smallest Number From DI String | permutation | url | |
| 1352. Product of the Last K Numbers | 累積和/掛け算版/0の位置を管理して位置以内であれば解を計算する | url | |
| 1910. Remove All Occurrences of a Substring | string find | url | |
| 2342. Max Sum of a Pair With Equal Sum of Digits | heapify/defaultdict | url | |
| 3066. Minimum Operations to Exceed Threshold Value II | heapify | url | |
| 1718. Construct the Lexicographically Largest Valid Sequence | 再帰/先頭から順に数字を埋めていく/最後まで進んだらOK | url | |
| 2698. Find the Punishment Number of an Integer | 再帰/左から分割して数値がゼロになる分割を見つける | url | |
| 1079. Letter Tile Possibilities | Permutations | url | |
| 3174. Clear Digits | append/pop | url | |
| 2364. Count Number of Bad Pairs | 問題文の言い換え/動的計画法/全探索 | url | |
| 2349. Design a Number Container System | 常に最新の値を管理する/クエリ時に最新情報と照合して正しい値を返す | url | |
| 3160. Find the Number of Distinct Colors Among the Balls | 色の数を管理 | url | |
| 1726. Tuple with Same Product | defaultdict()で掛け算の結果を管理/組合わせ | url | |
| 1790. Check if One String Swap Can Make Strings Equal | 文字列を比較 | url | |
| 1800. Maximum Ascending Subarray Sum | sumsを管理して最大を保存 | url | |
| 3152. Special Array II | 二分探索 | url | |
| 3105. Longest Strictly Increasing or Strictly Decreasing Subarray | 連続する増加/減少を管理 | url | |
| 827. Making A Large Island | unionfind/探索候補を全探索/上下左右の島をunionfindで管理して島のサイズを合算する | url | |
| 2493. Divide Nodes Into the Maximum Number of Groups | 全探索/幅優先探索で２部グラフ作成/独立する各グラフに対して最大のGroupを管理(unionfind) | url | |
| 3151. Special Array I | parityチェック/最後の1bitチェック | url | |
| 2658. Maximum Number of Fish in a Grid | BFS/幅優先探索 | url | |
| 684. Redundant Connection | unionfind | url | |
| 1462. Course Schedule IV | グラフ/BFS/親子関係 | url | |
| 802. Find Eventual Safe States | グラフ/逆方向 | url | |
| 2017. Grid Game | greedy search | url | |
| 1765. Map of Highest Peak | Breadth First Search | url | |
| 1267. Count Servers that Communicate | set/二次元 | url | |
| 2948. Make Lexicographically Smallest Array by Swapping Elements | グループ化して並び替え | url | |
| 2127. Maximum Employees to Be Invited to a Meeting | グラフサイクル検出/BFS/最長ループ探索 | - | - |
| 2661. First Completely Painted Row or Column | 訪れた座標を管理する/ビンゴゲームの要領でカウント | url | |
| 2116. Check if a Parentheses String Can Be Valid | 括弧の出現を管理する/unlockとlockを分けて、後ほど後ろから探索する | url | |
| 3042. Count Prefix and Suffix Pairs I | 文字列のprefix/suffixを比較する/全探索 | url | |
| 2185. Counting Words With a Given Prefix | 先頭から比較 | url | |
| https://leetcode.com/problems/word-subsets/submissions/1514050596/ | 言い換え:比較対象の文字列の出現数最大を管理して比較に使う | url | |
| 1400. Construct K Palindrome Strings | 文字の出現数をカウント/場合分け | url | |
| 3223. Minimum Length of String After Operations | 文字の出現数を管理 | url | |
| 2657. Find the Prefix Common Array of Two Arrays | 配列内の出現数を先頭からカウントする/DynamicProgramming | url | |
| 2429. Minimize XOR | bit数の計算/XOR演算による最小値を求める | url | |
| 2683. Neighboring Bitwise XOR | 愚直に先頭からシミュレーション、高々2通りしかない | url | |
| 2425. Bitwise XOR of All Pairings | XOR���交換法則が成り立つ）の計算順序を工夫、結局のところ奇数個登場する値のxorを求めればOK | url | - |
| 407. Trapping Rain Water II | BFS/周囲の壁を管理/最も高さの低い順に探索 | url | - |
| 1368. Minimum Cost to Make at Least One Valid Path in a Grid | BFS/4方向/最短コストを記憶 | url | - |
| 1408. String Matching in an Array | 全探索/BruteForce | url | |
| 1769. Minimum Number of Operations to Move All Balls to Each Box | 変化時の差分管理 | url | |
| 2381. Shifting Letters II | 一次元のいもす法 | url | |
| 1930. Unique Length-3 Palindromic Subsequences | 文字の位置を記憶する | url | |
| 2270. Number of Ways to Split Array | 差分管理 | url | |
| 2559. Count Vowel Strings | 累積和 | url | |
| 983. Minimum Cost For Tickets | dp | url | |
| 1422. Maximum Score After Splitting a String | 尺取り法 | url | |
| 2466. Count Ways To Build Good Strings | dp | url | |
| 1014. | DynamicProgramming | url | |
| 2872. | BFS/leef nodeから順番に探索、kの倍数で枝切り | url | |
| 2940. | defaultdict/二分探索 | url | |
| 2471. | binary tree/sort | url | |
| 3203. Find Minimum Diameter After Merging Two Trees | BFS/木の長さ | url | |
| 515. Find Largest Value in Each Tree Row | BFS | url | |
| 494. Target Sum | 全探索/DP | url | |
| - | - | - | - |