Leetcode Solutions
Table Of Contents
Description
This is a repo to store my leetcode solutions but I went a bit Schizo with it and it pulls the leetcode solutions, creates READMEs with the problema and solution and then converts it into an Mkdocs website hosted on GitHub Pages.
Steps
- Uses the
joshcai/leetcode-syncGitHub action to will the problems and solutions from leetcode into the/Solutionsfolder. - Uses the Script
update_project_readme.pyto compile all of the completed problems into a table in 2 readme files that can be used for GitHub and the Mkdocs site - Uses the Script
update_readmes.py.pyto create README files from the problems and solutions and embed their difficulty, tags and the solution's statistics. - Uses Mkdocs to convert the READMEs created in
Step 3to a website. - The website is then deployed using the GitHub Pages deploy action.
My Leetcode Stats
Table of my Solutions
| Problem | Solution | Difficulty | Tags |
|---|---|---|---|
| 1. Two Sum | 🔗 | Easy | Array, Hash Table |
| 2. Add Two Numbers | 🔗 | Medium | Linked List, Math, Recursion |
| 3. Longest Substring Without Repeating Characters | 🔗 | Medium | Hash Table, String, Sliding Window |
| 4. Median Of Two Sorted Arrays | 🔗 | Hard | Array, Binary Search, Divide and Conquer |
| 5. Longest Palindromic Substring | 🔗 | Medium | Two Pointers, String, Dynamic Programming |
| 6. Zigzag Conversion | 🔗 | Medium | String |
| 7. Reverse Integer | 🔗 | Medium | Math |
| 8. String To Integer Atoi | 🔗 | Medium | String |
| 9. Palindrome Number | 🔗 | Easy | Math |
| 10. Regular Expression Matching | 🔗 | Hard | String, Dynamic Programming, Recursion |
| 11. Container With Most Water | 🔗 | Medium | Array, Two Pointers, Greedy |
| 12. Integer To Roman | 🔗 | Medium | Hash Table, Math, String |
| 13. Roman To Integer | 🔗 | Easy | Hash Table, Math, String |
| 14. Longest Common Prefix | 🔗 | Easy | Array, String, Trie |
| 15. 3sum | 🔗 | Medium | Array, Two Pointers, Sorting |
| 16. 3sum Closest | 🔗 | Medium | Array, Two Pointers, Sorting |
| 17. Letter Combinations Of A Phone Number | 🔗 | Medium | Hash Table, String, Backtracking |
| 18. 4sum | 🔗 | Medium | Array, Two Pointers, Sorting |
| 19. Remove Nth Node From End Of List | 🔗 | Medium | Linked List, Two Pointers |
| 20. Valid Parentheses | 🔗 | Easy | String, Stack |
| 21. Merge Two Sorted Lists | 🔗 | Easy | Linked List, Recursion |
| 22. Generate Parentheses | 🔗 | Medium | String, Dynamic Programming, Backtracking |
| 23. Merge K Sorted Lists | 🔗 | Hard | Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort |
| 24. Swap Nodes In Pairs | 🔗 | Medium | Linked List, Recursion |
| 25. Reverse Nodes In K Group | 🔗 | Hard | Linked List, Recursion |
| 26. Remove Duplicates From Sorted Array | 🔗 | Easy | Array, Two Pointers |
| 27. Remove Element | 🔗 | Easy | Array, Two Pointers |
| 28. Find The Index Of The First Occurrence In A String | 🔗 | Easy | Two Pointers, String, String Matching |
| 29. Divide Two Integers | 🔗 | Medium | Math, Bit Manipulation |
| 30. Substring With Concatenation Of All Words | 🔗 | Hard | Hash Table, String, Sliding Window |
| 31. Next Permutation | 🔗 | Medium | Array, Two Pointers |
| 32. Longest Valid Parentheses | 🔗 | Hard | String, Dynamic Programming, Stack |
| 33. Search In Rotated Sorted Array | 🔗 | Medium | Array, Binary Search |
| 34. Find First And Last Position Of Element In Sorted Array | 🔗 | Medium | Array, Binary Search |
| 35. Search Insert Position | 🔗 | Easy | Array, Binary Search |
| 36. Valid Sudoku | 🔗 | Medium | Array, Hash Table, Matrix |
| 37. Sudoku Solver | 🔗 | Hard | Array, Hash Table, Backtracking, Matrix |
| 38. Count And Say | 🔗 | Medium | String |
| 39. Combination Sum | 🔗 | Medium | Array, Backtracking |
| 40. Combination Sum II | 🔗 | Medium | Array, Backtracking |
| 41. First Missing Positive | 🔗 | Hard | Array, Hash Table |
| 42. Trapping Rain Water | 🔗 | Hard | Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack |
| 43. Multiply Strings | 🔗 | Medium | Math, String, Simulation |
| 44. Wildcard Matching | 🔗 | Hard | String, Dynamic Programming, Greedy, Recursion |
| 45. Jump Game II | 🔗 | Medium | Array, Dynamic Programming, Greedy |
| 46. Permutations | 🔗 | Medium | Array, Backtracking |
| 47. Permutations II | 🔗 | Medium | Array, Backtracking, Sorting |
| 48. Rotate Image | 🔗 | Medium | Array, Math, Matrix |
| 49. Group Anagrams | 🔗 | Medium | Array, Hash Table, String, Sorting |
| 50. Powx N | 🔗 | Medium | Math, Recursion |
| 51. N Queens | 🔗 | Hard | Array, Backtracking |
| 52. N Queens II | 🔗 | Hard | Backtracking |
| 54. Spiral Matrix | 🔗 | Medium | Array, Matrix, Simulation |
| 55. Jump Game | 🔗 | Medium | Array, Dynamic Programming, Greedy |
| 56. Merge Intervals | 🔗 | Medium | Array, Sorting |
| 57. Insert Interval | 🔗 | Medium | Array |
| 58. Length Of Last Word | 🔗 | Easy | String |
| 59. Spiral Matrix II | 🔗 | Medium | Array, Matrix, Simulation |
| 62. Unique Paths | 🔗 | Medium | Math, Dynamic Programming, Combinatorics |
| 63. Unique Paths II | 🔗 | Medium | Array, Dynamic Programming, Matrix |
| 64. Minimum Path Sum | 🔗 | Medium | Array, Dynamic Programming, Matrix |
| 66. Plus One | 🔗 | Easy | Array, Math |
| 67. Add Binary | 🔗 | Easy | Math, String, Bit Manipulation, Simulation |
| 68. Text Justification | 🔗 | Hard | Array, String, Simulation |
| 69. Sqrtx | 🔗 | Easy | Math, Binary Search |
| 70. Climbing Stairs | 🔗 | Easy | Math, Dynamic Programming, Memoization |
| 72. Edit Distance | 🔗 | Medium | String, Dynamic Programming |
| 73. Set Matrix Zeroes | 🔗 | Medium | Array, Hash Table, Matrix |
| 74. Search A 2d Matrix | 🔗 | Medium | Array, Binary Search, Matrix |
| 76. Minimum Window Substring | 🔗 | Hard | Hash Table, String, Sliding Window |
| 78. Subsets | 🔗 | Medium | Array, Backtracking, Bit Manipulation |
| 79. Word Search | 🔗 | Medium | Array, String, Backtracking, Depth-First Search, Matrix |
| 80. Remove Duplicates From Sorted Array II | 🔗 | Medium | Array, Two Pointers |
| 81. Search In Rotated Sorted Array II | 🔗 | Medium | Array, Binary Search |
| 83. Remove Duplicates From Sorted List | 🔗 | Easy | Linked List |
| 84. Largest Rectangle In Histogram | 🔗 | Hard | Array, Stack, Monotonic Stack |
| 88. Merge Sorted Array | 🔗 | Easy | Array, Two Pointers, Sorting |
| 89. Gray Code | 🔗 | Medium | Math, Backtracking, Bit Manipulation |
| 90. Subsets II | 🔗 | Medium | Array, Backtracking, Bit Manipulation |
| 94. Binary Tree Inorder Traversal | 🔗 | Easy | Stack, Tree, Depth-First Search, Binary Tree |
| 96. Unique Binary Search Trees | 🔗 | Medium | Math, Dynamic Programming, Tree, Binary Search Tree, Binary Tree |
| 98. Validate Binary Search Tree | 🔗 | Medium | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
| 99. Recover Binary Search Tree | 🔗 | Medium | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
| 100. Same Tree | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 101. Symmetric Tree | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 104. Maximum Depth Of Binary Tree | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 105. Construct Binary Tree From Preorder And Inorder Traversal | 🔗 | Medium | Array, Hash Table, Divide and Conquer, Tree, Binary Tree |
| 106. Construct Binary Tree From Inorder And Postorder Traversal | 🔗 | Medium | Array, Hash Table, Divide and Conquer, Tree, Binary Tree |
| 108. Convert Sorted Array To Binary Search Tree | 🔗 | Easy | Array, Divide and Conquer, Tree, Binary Search Tree, Binary Tree |
| 110. Balanced Binary Tree | 🔗 | Easy | Tree, Depth-First Search, Binary Tree |
| 111. Minimum Depth Of Binary Tree | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 112. Path Sum | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 113. Path Sum II | 🔗 | Medium | Backtracking, Tree, Depth-First Search, Binary Tree |
| 114. Flatten Binary Tree To Linked List | 🔗 | Medium | Linked List, Stack, Tree, Depth-First Search, Binary Tree |
| 115. Distinct Subsequences | 🔗 | Hard | String, Dynamic Programming |
| 116. Populating Next Right Pointers In Each Node | 🔗 | Medium | Linked List, Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 117. Populating Next Right Pointers In Each Node II | 🔗 | Medium | Linked List, Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 118. Pascals Triangle | 🔗 | Easy | Array, Dynamic Programming |
| 119. Pascals Triangle II | 🔗 | Easy | Array, Dynamic Programming |
| 120. Triangle | 🔗 | Medium | Array, Dynamic Programming |
| 121. Best Time To Buy And Sell Stock | 🔗 | Easy | Array, Dynamic Programming |
| 122. Best Time To Buy And Sell Stock II | 🔗 | Medium | Array, Dynamic Programming, Greedy |
| 123. Best Time To Buy And Sell Stock III | 🔗 | Hard | Array, Dynamic Programming |
| 129. Sum Root To Leaf Numbers | 🔗 | Medium | Tree, Depth-First Search, Binary Tree |
| 130. Surrounded Regions | 🔗 | Medium | Array, Depth-First Search, Breadth-First Search, Union Find, Matrix |
| 133. Clone Graph | 🔗 | Medium | Hash Table, Depth-First Search, Breadth-First Search, Graph |
| 134. Gas Station | 🔗 | Medium | Array, Greedy |
| 135. Candy | 🔗 | Hard | Array, Greedy |
| 136. Single Number | 🔗 | Easy | Array, Bit Manipulation |
| 137. Single Number II | 🔗 | Medium | Array, Bit Manipulation |
| 139. Word Break | 🔗 | Medium | Array, Hash Table, String, Dynamic Programming, Trie, Memoization |
| 141. Linked List Cycle | 🔗 | Easy | Hash Table, Linked List, Two Pointers |
| 144. Binary Tree Preorder Traversal | 🔗 | Easy | Stack, Tree, Depth-First Search, Binary Tree |
| 145. Binary Tree Postorder Traversal | 🔗 | Easy | Stack, Tree, Depth-First Search, Binary Tree |
| 146. Lru Cache | 🔗 | Medium | Hash Table, Linked List, Design, Doubly-Linked List |
| 153. Find Minimum In Rotated Sorted Array | 🔗 | Medium | Array, Binary Search |
| 154. Find Minimum In Rotated Sorted Array II | 🔗 | Hard | Array, Binary Search |
| 162. Find Peak Element | 🔗 | Medium | Array, Binary Search |
| 165. Compare Version Numbers | 🔗 | Medium | Two Pointers, String |
| 166. Fraction To Recurring Decimal | 🔗 | Medium | Hash Table, Math, String |
| 167. Two Sum II Input Array Is Sorted | 🔗 | Medium | Array, Two Pointers, Binary Search |
| 169. Majority Element | 🔗 | Easy | Array, Hash Table, Divide and Conquer, Sorting, Counting |
| 175. Combine Two Tables | 🔗 | Easy | Database |
| 176. Second Highest Salary | 🔗 | Medium | Database |
| 177. Nth Highest Salary | 🔗 | Medium | Database |
| 178. Rank Scores | 🔗 | Medium | Database |
| 179. Largest Number | 🔗 | Medium | Array, String, Greedy, Sorting |
| 181. Employees Earning More Than Their Managers | 🔗 | Easy | Database |
| 182. Duplicate Emails | 🔗 | Easy | Database |
| 183. Customers Who Never Order | 🔗 | Easy | Database |
| 184. Department Highest Salary | 🔗 | Medium | Database |
| 185. Department Top Three Salaries | 🔗 | Hard | Database |
| 187. Repeated Dna Sequences | 🔗 | Medium | Hash Table, String, Bit Manipulation, Sliding Window, Rolling Hash, Hash Function |
| 188. Best Time To Buy And Sell Stock IV | 🔗 | Hard | Array, Dynamic Programming |
| 190. Reverse Bits | 🔗 | Easy | Divide and Conquer, Bit Manipulation |
| 191. Number Of 1 Bits | 🔗 | Easy | Divide and Conquer, Bit Manipulation |
| 196. Delete Duplicate Emails | 🔗 | Easy | Database |
| 197. Rising Temperature | 🔗 | Easy | Database |
| 198. House Robber | 🔗 | Medium | Array, Dynamic Programming |
| 199. Binary Tree Right Side View | 🔗 | Medium | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 200. Number Of Islands | 🔗 | Medium | Array, Depth-First Search, Breadth-First Search, Union Find, Matrix |
| 201. Bitwise And Of Numbers Range | 🔗 | Medium | Bit Manipulation |
| 203. Remove Linked List Elements | 🔗 | Easy | Linked List, Recursion |
| 206. Reverse Linked List | 🔗 | Easy | Linked List, Recursion |
| 207. Course Schedule | 🔗 | Medium | Depth-First Search, Breadth-First Search, Graph, Topological Sort |
| 209. Minimum Size Subarray Sum | 🔗 | Medium | Array, Binary Search, Sliding Window, Prefix Sum |
| 210. Course Schedule II | 🔗 | Medium | Depth-First Search, Breadth-First Search, Graph, Topological Sort |
| 215. Kth Largest Element In An Array | 🔗 | Medium | Array, Divide and Conquer, Sorting, Heap (Priority Queue), Quickselect |
| 217. Contains Duplicate | 🔗 | Easy | Array, Hash Table, Sorting |
| 218. The Skyline Problem | 🔗 | Hard | Array, Divide and Conquer, Binary Indexed Tree, Segment Tree, Line Sweep, Sorting, Heap (Priority Queue), Ordered Set |
| 221. Maximal Square | 🔗 | Medium | Array, Dynamic Programming, Matrix |
| 222. Count Complete Tree Nodes | 🔗 | Easy | Binary Search, Bit Manipulation, Tree, Binary Tree |
| 226. Invert Binary Tree | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 231. Power Of Two | 🔗 | Easy | Math, Bit Manipulation, Recursion |
| 234. Palindrome Linked List | 🔗 | Easy | Linked List, Two Pointers, Stack, Recursion |
| 237. Delete Node In A Linked List | 🔗 | Medium | Linked List |
| 238. Product Of Array Except Self | 🔗 | Medium | Array, Prefix Sum |
| 239. Sliding Window Maximum | 🔗 | Hard | Array, Queue, Sliding Window, Heap (Priority Queue), Monotonic Queue |
| 240. Search A 2d Matrix II | 🔗 | Medium | Array, Binary Search, Divide and Conquer, Matrix |
| 257. Binary Tree Paths | 🔗 | Easy | String, Backtracking, Tree, Depth-First Search, Binary Tree |
| 260. Single Number III | 🔗 | Medium | Array, Bit Manipulation |
| 264. Ugly Number II | 🔗 | Medium | Hash Table, Math, Dynamic Programming, Heap (Priority Queue) |
| 268. Missing Number | 🔗 | Easy | Array, Hash Table, Math, Binary Search, Bit Manipulation, Sorting |
| 275. H Index II | 🔗 | Medium | Array, Binary Search |
| 278. First Bad Version | 🔗 | Easy | Binary Search, Interactive |
| 283. Move Zeroes | 🔗 | Easy | Array, Two Pointers |
| 287. Find The Duplicate Number | 🔗 | Medium | Array, Two Pointers, Binary Search, Bit Manipulation |
| 295. Find Median From Data Stream | 🔗 | Hard | Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream |
| 300. Longest Increasing Subsequence | 🔗 | Medium | Array, Binary Search, Dynamic Programming |
| 303. Range Sum Query Immutable | 🔗 | Easy | Array, Design, Prefix Sum |
| 309. Best Time To Buy And Sell Stock With Cooldown | 🔗 | Medium | Array, Dynamic Programming |
| 315. Count Of Smaller Numbers After Self | 🔗 | Hard | Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set |
| 316. Remove Duplicate Letters | 🔗 | Medium | String, Stack, Greedy, Monotonic Stack |
| 321. Create Maximum Number | 🔗 | Hard | Array, Two Pointers, Stack, Greedy, Monotonic Stack |
| 324. Wiggle Sort II | 🔗 | Medium | Array, Divide and Conquer, Greedy, Sorting, Quickselect |
| 326. Power Of Three | 🔗 | Easy | Math, Recursion |
| 327. Count Of Range Sum | 🔗 | Hard | Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set |
| 330. Patching Array | 🔗 | Hard | Array, Greedy |
| 334. Increasing Triplet Subsequence | 🔗 | Medium | Array, Greedy |
| 338. Counting Bits | 🔗 | Easy | Dynamic Programming, Bit Manipulation |
| 342. Power Of Four | 🔗 | Easy | Math, Bit Manipulation, Recursion |
| 347. Top K Frequent Elements | 🔗 | Medium | Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect |
| 349. Intersection Of Two Arrays | 🔗 | Easy | Array, Hash Table, Two Pointers, Binary Search, Sorting |
| 350. Intersection Of Two Arrays II | 🔗 | Easy | Array, Hash Table, Two Pointers, Binary Search, Sorting |
| 352. Data Stream As Disjoint Intervals | 🔗 | Hard | Binary Search, Design, Ordered Set |
| 354. Russian Doll Envelopes | 🔗 | Hard | Array, Binary Search, Dynamic Programming, Sorting |
| 355. Design Twitter | 🔗 | Medium | Hash Table, Linked List, Design, Heap (Priority Queue) |
| 363. Max Sum Of Rectangle No Larger Than K | 🔗 | Hard | Array, Binary Search, Matrix, Prefix Sum, Ordered Set |
| 367. Valid Perfect Square | 🔗 | Easy | Math, Binary Search |
| 371. Sum Of Two Integers | 🔗 | Medium | Math, Bit Manipulation |
| 373. Find K Pairs With Smallest Sums | 🔗 | Medium | Array, Heap (Priority Queue) |
| 374. Guess Number Higher Or Lower | 🔗 | Easy | Binary Search, Interactive |
| 376. Wiggle Subsequence | 🔗 | Medium | Array, Dynamic Programming, Greedy |
| 378. Kth Smallest Element In A Sorted Matrix | 🔗 | Medium | Array, Binary Search, Sorting, Heap (Priority Queue), Matrix |
| 389. Find The Difference | 🔗 | Easy | Hash Table, String, Bit Manipulation, Sorting |
| 392. Is Subsequence | 🔗 | Easy | Two Pointers, String, Dynamic Programming |
| 397. Integer Replacement | 🔗 | Medium | Dynamic Programming, Greedy, Bit Manipulation, Memoization |
| 400. Nth Digit | 🔗 | Medium | Math, Binary Search |
| 401. Binary Watch | 🔗 | Easy | Backtracking, Bit Manipulation |
| 402. Remove K Digits | 🔗 | Medium | String, Stack, Greedy, Monotonic Stack |
| 404. Sum Of Left Leaves | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 405. Convert A Number To Hexadecimal | 🔗 | Easy | Math, String, Bit Manipulation |
| 407. Trapping Rain Water II | 🔗 | Hard | Array, Breadth-First Search, Heap (Priority Queue), Matrix |
| 409. Longest Palindrome | 🔗 | Easy | Hash Table, String, Greedy |
| 410. Split Array Largest Sum | 🔗 | Hard | Array, Binary Search, Dynamic Programming, Greedy, Prefix Sum |
| 412. Fizz Buzz | 🔗 | Easy | Math, String, Simulation |
| 414. Third Maximum Number | 🔗 | Easy | Array, Sorting |
| 417. Pacific Atlantic Water Flow | 🔗 | Medium | Array, Depth-First Search, Breadth-First Search, Matrix |
| 421. Maximum Xor Of Two Numbers In An Array | 🔗 | Medium | Array, Hash Table, Bit Manipulation, Trie |
| 434. Number Of Segments In A String | 🔗 | Easy | String |
| 436. Find Right Interval | 🔗 | Medium | Array, Binary Search, Sorting |
| 441. Arranging Coins | 🔗 | Easy | Math, Binary Search |
| 442. Find All Duplicates In An Array | 🔗 | Medium | Array, Hash Table |
| 448. Find All Numbers Disappeared In An Array | 🔗 | Easy | Array, Hash Table |
| 451. Sort Characters By Frequency | 🔗 | Medium | Hash Table, String, Sorting, Heap (Priority Queue), Bucket Sort, Counting |
| 455. Assign Cookies | 🔗 | Easy | Array, Two Pointers, Greedy, Sorting |
| 456. 132 Pattern | 🔗 | Medium | Array, Binary Search, Stack, Monotonic Stack, Ordered Set |
| 459. Repeated Substring Pattern | 🔗 | Easy | String, String Matching |
| 461. Hamming Distance | 🔗 | Easy | Bit Manipulation |
| 463. Island Perimeter | 🔗 | Easy | Array, Depth-First Search, Breadth-First Search, Matrix |
| 464. Can I Win | 🔗 | Medium | Math, Dynamic Programming, Bit Manipulation, Memoization, Game Theory, Bitmask |
| 473. Matchsticks To Square | 🔗 | Medium | Array, Dynamic Programming, Backtracking, Bit Manipulation, Bitmask |
| 476. Number Complement | 🔗 | Easy | Bit Manipulation |
| 477. Total Hamming Distance | 🔗 | Medium | Array, Math, Bit Manipulation |
| 482. License Key Formatting | 🔗 | Easy | String |
| 485. Max Consecutive Ones | 🔗 | Easy | Array |
| 491. Non Decreasing Subsequences | 🔗 | Medium | Array, Hash Table, Backtracking, Bit Manipulation |
| 492. Construct The Rectangle | 🔗 | Easy | Math |
| 495. Teemo Attacking | 🔗 | Easy | Array, Simulation |
| 496. Next Greater Element I | 🔗 | Easy | Array, Hash Table, Stack, Monotonic Stack |
| 498. Diagonal Traverse | 🔗 | Medium | Array, Matrix, Simulation |
| 500. Keyboard Row | 🔗 | Easy | Array, Hash Table, String |
| 501. Find Mode In Binary Search Tree | 🔗 | Easy | Tree, Depth-First Search, Binary Search Tree, Binary Tree |
| 502. Ipo | 🔗 | Hard | Array, Greedy, Sorting, Heap (Priority Queue) |
| 504. Base 7 | 🔗 | Easy | Math, String |
| 506. Relative Ranks | 🔗 | Easy | Array, Sorting, Heap (Priority Queue) |
| 507. Perfect Number | 🔗 | Easy | Math |
| 516. Longest Palindromic Subsequence | 🔗 | Medium | String, Dynamic Programming |
| 520. Detect Capital | 🔗 | Easy | String |
| 521. Longest Uncommon Subsequence I | 🔗 | Easy | String |
| 530. Minimum Absolute Difference In Bst | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Search Tree, Binary Tree |
| 541. Reverse String II | 🔗 | Easy | Two Pointers, String |
| 543. Diameter Of Binary Tree | 🔗 | Easy | Tree, Depth-First Search, Binary Tree |
| 551. Student Attendance Record I | 🔗 | Easy | String |
| 557. Reverse Words In A String III | 🔗 | Easy | Two Pointers, String |
| 561. Array Partition | 🔗 | Easy | Array, Greedy, Sorting, Counting Sort |
| 563. Binary Tree Tilt | 🔗 | Easy | Tree, Depth-First Search, Binary Tree |
| 566. Reshape The Matrix | 🔗 | Easy | Array, Matrix, Simulation |
| 567. Permutation In String | 🔗 | Medium | Hash Table, Two Pointers, String, Sliding Window |
| 570. Managers With At Least 5 Direct Reports | 🔗 | Medium | Database |
| 572. Subtree Of Another Tree | 🔗 | Easy | Tree, Depth-First Search, String Matching, Binary Tree, Hash Function |
| 575. Distribute Candies | 🔗 | Easy | Array, Hash Table |
| 577. Employee Bonus | 🔗 | Easy | Database |
| 584. Find Customer Referee | 🔗 | Easy | Database |
| 586. Customer Placing The Largest Number Of Orders | 🔗 | Easy | Database |
| 594. Longest Harmonious Subsequence | 🔗 | Easy | Array, Hash Table, Sliding Window, Sorting, Counting |
| 595. Big Countries | 🔗 | Easy | Database |
| 596. Classes With At Least 5 Students | 🔗 | Easy | Database |
| 598. Range Addition II | 🔗 | Easy | Array, Math |
| 599. Minimum Index Sum Of Two Lists | 🔗 | Easy | Array, Hash Table, String |
| 601. Human Traffic Of Stadium | 🔗 | Hard | Database |
| 602. Friend Requests II Who Has The Most Friends | 🔗 | Medium | Database |
| 605. Can Place Flowers | 🔗 | Easy | Array, Greedy |
| 607. Sales Person | 🔗 | Easy | Database |
| 608. Tree Node | 🔗 | Medium | Database |
| 610. Triangle Judgement | 🔗 | Easy | Database |
| 611. Valid Triangle Number | 🔗 | Medium | Array, Two Pointers, Binary Search, Greedy, Sorting |
| 617. Merge Two Binary Trees | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 619. Biggest Single Number | 🔗 | Easy | Database |
| 620. Not Boring Movies | 🔗 | Easy | Database |
| 621. Task Scheduler | 🔗 | Medium | Array, Hash Table, Greedy, Sorting, Heap (Priority Queue), Counting |
| 626. Exchange Seats | 🔗 | Medium | Database |
| 627. Swap Salary | 🔗 | Easy | Database |
| 628. Maximum Product Of Three Numbers | 🔗 | Easy | Array, Math, Sorting |
| 637. Average Of Levels In Binary Tree | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search, Binary Tree |
| 643. Maximum Average Subarray I | 🔗 | Easy | Array, Sliding Window |
| 645. Set Mismatch | 🔗 | Easy | Array, Hash Table, Bit Manipulation, Sorting |
| 646. Maximum Length Of Pair Chain | 🔗 | Medium | Array, Dynamic Programming, Greedy, Sorting |
| 653. Two Sum IV Input Is A Bst | 🔗 | Easy | Hash Table, Two Pointers, Tree, Depth-First Search, Breadth-First Search, Binary Search Tree, Binary Tree |
| 657. Robot Return To Origin | 🔗 | Easy | String, Simulation |
| 658. Find K Closest Elements | 🔗 | Medium | Array, Two Pointers, Binary Search, Sliding Window, Sorting, Heap (Priority Queue) |
| 659. Split Array Into Consecutive Subsequences | 🔗 | Medium | Array, Hash Table, Greedy, Heap (Priority Queue) |
| 661. Image Smoother | 🔗 | Easy | Array, Matrix |
| 671. Second Minimum Node In A Binary Tree | 🔗 | Easy | Tree, Depth-First Search, Binary Tree |
| 673. Number Of Longest Increasing Subsequence | 🔗 | Medium | Array, Dynamic Programming, Binary Indexed Tree, Segment Tree |
| 674. Longest Continuous Increasing Subsequence | 🔗 | Easy | Array |
| 679. 24 Game | 🔗 | Hard | Array, Math, Backtracking |
| 680. Valid Palindrome II | 🔗 | Easy | Two Pointers, String, Greedy |
| 682. Baseball Game | 🔗 | Easy | Array, Stack, Simulation |
| 692. Top K Frequent Words | 🔗 | Medium | Array, Hash Table, String, Trie, Sorting, Heap (Priority Queue), Bucket Sort, Counting |
| 693. Binary Number With Alternating Bits | 🔗 | Easy | Bit Manipulation |
| 696. Count Binary Substrings | 🔗 | Easy | Two Pointers, String |
| 697. Degree Of An Array | 🔗 | Easy | Array, Hash Table |
| 712. Minimum Ascii Delete Sum For Two Strings | 🔗 | Medium | String, Dynamic Programming |
| 714. Best Time To Buy And Sell Stock With Transaction Fee | 🔗 | Medium | Array, Dynamic Programming, Greedy |
| 717. 1 Bit And 2 Bit Characters | 🔗 | Easy | Array |
| 724. Find Pivot Index | 🔗 | Easy | Array, Prefix Sum |
| 728. Self Dividing Numbers | 🔗 | Easy | Math |
| 733. Flood Fill | 🔗 | Easy | Array, Depth-First Search, Breadth-First Search, Matrix |
| 740. Delete And Earn | 🔗 | Medium | Array, Hash Table, Dynamic Programming |
| 742. To Lower Case | 🔗 | Easy | String |
| 744. Network Delay Time | 🔗 | Medium | Depth-First Search, Breadth-First Search, Graph, Heap (Priority Queue), Shortest Path |
| 745. Find Smallest Letter Greater Than Target | 🔗 | Easy | Array, Binary Search |
| 747. Min Cost Climbing Stairs | 🔗 | Easy | Array, Dynamic Programming |
| 748. Largest Number At Least Twice Of Others | 🔗 | Easy | Array, Sorting |
| 749. Shortest Completing Word | 🔗 | Easy | Array, Hash Table, String |
| 774. Maximum Depth Of N Ary Tree | 🔗 | Easy | Tree, Depth-First Search, Breadth-First Search |
| 775. N Ary Tree Preorder Traversal | 🔗 | Easy | Stack, Tree, Depth-First Search |
| 776. N Ary Tree Postorder Traversal | 🔗 | Easy | Stack, Tree, Depth-First Search |
| 778. Reorganize String | 🔗 | Medium | Hash Table, String, Greedy, Sorting, Heap (Priority Queue), Counting |
| 783. Search In A Binary Search Tree | 🔗 | Easy | Tree, Binary Search Tree, Binary Tree |
| 784. Insert Into A Binary Search Tree | 🔗 | Medium | Tree, Binary Search Tree, Binary Tree |
| 789. Kth Largest Element In A Stream | 🔗 | Easy | Tree, Design, Binary Search Tree, Heap (Priority Queue), Binary Tree, Data Stream |
| 792. Binary Search | 🔗 | Easy | Array, Binary Search |
| 794. Swim In Rising Water | 🔗 | Hard | Array, Binary Search, Depth-First Search, Breadth-First Search, Union Find, Heap (Priority Queue), Matrix |
| 802. K Th Smallest Prime Fraction | 🔗 | Medium | Array, Two Pointers, Binary Search, Sorting, Heap (Priority Queue) |
| 803. Cheapest Flights Within K Stops | 🔗 | Medium | Dynamic Programming, Depth-First Search, Breadth-First Search, Graph, Heap (Priority Queue), Shortest Path |
| 816. Design Hashset | 🔗 | Easy | Array, Hash Table, Linked List, Design, Hash Function |
| 817. Design Hashmap | 🔗 | Easy | Array, Hash Table, Linked List, Design, Hash Function |
| 826. Soup Servings | 🔗 | Medium | Math, Dynamic Programming, Probability and Statistics |
| 829. Subdomain Visit Count | 🔗 | Medium | Array, Hash Table, String, Counting |
| 830. Largest Triangle Area | 🔗 | Easy | Array, Math, Geometry |
| 867. New 21 Game | 🔗 | Medium | Math, Dynamic Programming, Sliding Window, Probability and Statistics |
| 874. Backspace String Compare | 🔗 | Easy | Two Pointers, String, Stack, Simulation |
| 879. Maximize Distance To Closest Person | 🔗 | Medium | Array |
| 882. Peak Index In A Mountain Array | 🔗 | Medium | Array, Binary Search |
| 900. Reordered Power Of 2 | 🔗 | Medium | Hash Table, Math, Sorting, Counting, Enumeration |
| 908. Middle Of The Linked List | 🔗 | Easy | Linked List, Two Pointers |
| 940. Fruit Into Baskets | 🔗 | Medium | Array, Hash Table, Sliding Window |
| 967. Minimum Falling Path Sum | 🔗 | Medium | Array, Dynamic Programming, Matrix |
| 1006. Vowel Spellchecker | 🔗 | Medium | Array, Hash Table, String |
| 1013. Fibonacci Number | 🔗 | Easy | Math, Dynamic Programming, Recursion, Memoization |
| 1018. Largest Perimeter Triangle | 🔗 | Easy | Array, Math, Greedy, Sorting |
| 1019. Squares Of A Sorted Array | 🔗 | Easy | Array, Two Pointers, Sorting |
| 1054. Complement Of Base 10 Integer | 🔗 | Easy | Bit Manipulation |
| 1087. Longest Arithmetic Subsequence | 🔗 | Medium | Array, Hash Table, Binary Search, Dynamic Programming |
| 1105. Uncrossed Lines | 🔗 | Medium | Array, Dynamic Programming |
| 1111. Minimum Score Triangulation Of Polygon | 🔗 | Medium | Array, Dynamic Programming |
| 1135. Customers Who Bought All Products | 🔗 | Medium | Database |
| 1153. Product Sales Analysis I | 🔗 | Easy | Database |
| 1179. Game Play Analysis I | 🔗 | Easy | Database |
| 1182. Game Play Analysis IV | 🔗 | Medium | Database |
| 1236. N Th Tribonacci Number | 🔗 | Easy | Math, Dynamic Programming, Memoization |
| 1245. User Activity For The Past 30 Days I | 🔗 | Easy | Database |
| 1250. Longest Common Subsequence | 🔗 | Medium | String, Dynamic Programming |
| 1258. Article Views I | 🔗 | Easy | Database |
| 1264. Maximum Number Of Words You Can Type | 🔗 | Easy | Hash Table, String |
| 1330. Longest Arithmetic Subsequence Of Given Difference | 🔗 | Medium | Array, Hash Table, Dynamic Programming |
| 1353. Find Resultant Array After Removing Anagrams | 🔗 | Easy | Array, Hash Table, String, Sorting |
| 1364. Tuple With Same Product | 🔗 | Medium | Array, Hash Table, Counting |
| 1370. Count Number Of Nice Subarrays | 🔗 | Medium | Array, Hash Table, Math, Sliding Window, Prefix Sum |
| 1390. Average Selling Price | 🔗 | Easy | Database |
| 1402. Count Square Submatrices With All Ones | 🔗 | Medium | Array, Dynamic Programming, Matrix |
| 1407. Group The People Given The Group Size They Belong To | 🔗 | Medium | Array, Hash Table, Greedy |
| 1411. Convert Binary Number In A Linked List To Integer | 🔗 | Easy | Linked List, Math |
| 1415. Students And Examinations | 🔗 | Easy | Database |
| 1421. Find Numbers With Even Number Of Digits | 🔗 | Easy | Array, Math |
| 1423. Maximum Number Of Occurrences Of A Substring | 🔗 | Medium | Hash Table, String, Sliding Window |
| 1426. Find N Unique Integers Sum Up To Zero | 🔗 | Easy | Array, Math |
| 1437. Minimum Insertion Steps To Make A String Palindrome | 🔗 | Hard | String, Dynamic Programming |
| 1440. Convert Integer To The Sum Of Two No Zero Integers | 🔗 | Easy | Math |
| 1448. Maximum 69 Number | 🔗 | Easy | Math, Greedy |
| 1509. Replace Employee Id With The Unique Identifier | 🔗 | Easy | Database |
| 1582. Design Browser History | 🔗 | Medium | Array, Linked List, Stack, Design, Doubly-Linked List, Data Stream |
| 1586. Longest Subarray Of 1s After Deleting One Element | 🔗 | Medium | Array, Dynamic Programming, Sliding Window |
| 1612. Avoid Flood In The City | 🔗 | Medium | Array, Hash Table, Binary Search, Greedy, Heap (Priority Queue) |
| 1619. Path Crossing | 🔗 | Easy | Hash Table, String |
| 1628. Count Submatrices With All Ones | 🔗 | Medium | Array, Dynamic Programming, Stack, Matrix, Monotonic Stack |
| 1642. Water Bottles | 🔗 | Easy | Math, Simulation |
| 1675. Magnetic Force Between Two Balls | 🔗 | Medium | Array, Binary Search, Sorting |
| 1765. Merge In Between Linked Lists | 🔗 | Medium | Linked List |
| 1827. Invalid Tweets | 🔗 | Easy | Database |
| 1834. Minimum Number Of People To Teach | 🔗 | Medium | Array, Hash Table, Greedy |
| 1908. Recyclable And Low Fat Products | 🔗 | Easy | Database |
| 1917. Maximum Average Pass Ratio | 🔗 | Medium | Array, Greedy, Heap (Priority Queue) |
| 1923. Sentence Similarity III | 🔗 | Medium | Array, Two Pointers, String |
| 2006. Find The Student That Will Replace The Chalk | 🔗 | Medium | Array, Binary Search, Simulation, Prefix Sum |
| 2023. Design Movie Rental System | 🔗 | Hard | Array, Hash Table, Design, Heap (Priority Queue), Ordered Set |
| 2076. Sum Of Digits Of String After Convert | 🔗 | Easy | String, Simulation |
| 2096. Find The Longest Valid Obstacle Course At Each Position | 🔗 | Hard | Array, Binary Search, Binary Indexed Tree |
| 2102. Find The Middle Index In Array | 🔗 | Easy | Array, Prefix Sum |
| 2132. Convert 1d Array Into 2d Array | 🔗 | Easy | Array, Matrix, Simulation |
| 2174. Next Greater Numerically Balanced Number | 🔗 | Medium | Hash Table, Math, Backtracking, Counting, Enumeration |
| 2229. Maximum Fruits Harvested After At Most K Steps | 🔗 | Hard | Array, Binary Search, Sliding Window, Prefix Sum |
| 2307. Replace Non Coprime Numbers In Array | 🔗 | Hard | Array, Math, Stack, Number Theory |
| 2316. Count Hills And Valleys In An Array | 🔗 | Easy | Array |
| 2324. Find Triangular Sum Of An Array | 🔗 | Medium | Array, Math, Simulation, Combinatorics |
| 2346. Largest 3 Same Digit Number In String | 🔗 | Easy | String |
| 2392. Successful Pairs Of Spells And Potions | 🔗 | Medium | Array, Two Pointers, Binary Search, Sorting |
| 2408. Number Of People Aware Of A Secret | 🔗 | Medium | Dynamic Programming, Queue, Simulation |
| 2429. Design A Food Rating System | 🔗 | Medium | Array, Hash Table, String, Design, Heap (Priority Queue), Ordered Set |
| 2432. Number Of Zero Filled Subarrays | 🔗 | Medium | Array, Math |
| 2497. Maximum Matching Of Players With Trainers | 🔗 | Medium | Array, Two Pointers, Greedy, Sorting |
| 2529. Range Product Queries Of Powers | 🔗 | Medium | Array, Bit Manipulation, Prefix Sum |
| 2689. Rearranging Fruits | 🔗 | Hard | Array, Hash Table, Greedy, Sort |
| 2734. Array Prototype Last | 🔗 | Easy | |
| 2758. Check If Object Instance Of Class | 🔗 | Medium | |
| 2837. Minimum Operations To Make The Integer Zero | 🔗 | Medium | Bit Manipulation, Brainteaser, Enumeration |
| 2882. Ways To Express An Integer As Sum Of Powers | 🔗 | Medium | Dynamic Programming |
| 2887. Sort Vowels In A String | 🔗 | Medium | String, Sorting |
| 3242. Count Elements With Maximum Frequency | 🔗 | Easy | Array, Hash Table, Counting |
| 3251. Maximum Area Of Longest Diagonal Rectangle | 🔗 | Easy | Array |
| 3277. Find The Number Of Ways To Place People II | 🔗 | Hard | Array, Math, Geometry, Sorting, Enumeration |
| 3278. Find The Number Of Ways To Place People I | 🔗 | Medium | Array, Math, Geometry, Sorting, Enumeration |
| 3279. Alice And Bob Playing Flower Game | 🔗 | Medium | Math |
| 3336. Water Bottles II | 🔗 | Medium | Math, Simulation |
| 3383. Taking Maximum Energy From The Mystic Dungeon | 🔗 | Medium | Array, Prefix Sum |
| 3437. Maximum Total Damage With Spell Casting | 🔗 | Medium | Array, Hash Table, Two Pointers, Binary Search, Dynamic Programming, Sorting, Counting |
| 3459. Find The Minimum Area To Cover All Ones II | 🔗 | Hard | Array, Matrix, Enumeration |
| 3461. Find The Minimum Area To Cover All Ones I | 🔗 | Medium | Array, Matrix |
| 3462. Vowels Game In A String | 🔗 | Medium | Math, String, Brainteaser, Game Theory |
| 3612. Adjacent Increasing Subarrays Detection I | 🔗 | Easy | Array |
| 3619. Adjacent Increasing Subarrays Detection II | 🔗 | Medium | Array, Binary Search |
| 3648. Find The Maximum Number Of Fruits Collected | 🔗 | Hard | Array, Dynamic Programming, Matrix |
| 3678. Design Task Manager | 🔗 | Medium | Hash Table, Design, Heap (Priority Queue), Ordered Set |
| 3733. Length Of Longest V Shaped Diagonal Segment | 🔗 | Hard | Array, Dynamic Programming, Memoization, Matrix |
| 3744. Minimum Operations To Make Array Elements Zero | 🔗 | Hard | Array, Math, Bit Manipulation |
| 3748. Sort Matrix By Diagonals | 🔗 | Medium | Array, Sorting, Matrix |
| 3790. Fruits Into Baskets II | 🔗 | Easy | Array, Binary Search, Segment Tree, Simulation, Ordered Set |
| 3791. Fruits Into Baskets III | 🔗 | Medium | Array, Binary Search, Segment Tree, Ordered Set |
| 3794. Find The Minimum Amount Of Time To Brew Potions | 🔗 | Medium | Array, Simulation, Prefix Sum |
| 3797. Design Spreadsheet | 🔗 | Medium | Array, Hash Table, String, Design, Matrix |
| 3827. Implement Router | 🔗 | Medium | Array, Hash Table, Binary Search, Design, Queue, Ordered Set |
| 3830. Find Closest Person | 🔗 | Easy | Math |
| 3851. Find Sum Of Array Product Of Magical Sequences | 🔗 | Hard | Array, Math, Dynamic Programming, Bit Manipulation, Combinatorics, Bitmask |
| 3872. Find Most Frequent Vowel And Consonant | 🔗 | Easy | Hash Table, String, Counting |