| 1. Two Sum |
Solution |
Easy |
| 2. Add Two Numbers |
Solution |
Medium |
| 3. Longest Substring Without Repeating Characters |
Solution |
Medium |
| 4. Median of Two Sorted Arrays |
Solution |
Hard |
| 5. Longest Palindromic Substring |
Solution |
Medium |
| 9. Palindrome Number |
Solution |
Easy |
| 8. String to Integer (atoi) |
Solution |
Medium |
| 10. Regular Expression Matching |
Solution |
Hard |
| 11. Container With Most Water |
Solution |
Medium |
| 12. Integer to Roman |
Solution |
Medium |
| 13. Roman to Integer |
Solution |
Easy |
| 14. Longest Common Prefix |
Solution |
Easy |
| 15. 3Sum |
Solution |
Medium |
| 16. 3Sum Closest |
Solution |
Medium |
| 17. Letter Combinations of a Phone Number |
Solution |
Medium |
| 18. 4Sum |
Solution |
Medium |
| 19. Remove Nth Node From End of List |
Solution |
Medium |
| 20. Valid Parentheses |
Solution |
Easy |
| 21. Merge Two Sorted Lists |
Solution |
Easy |
| 22. Generate Parentheses |
Solution |
Medium |
| 23. Merge k Sorted Lists |
Solution |
Hard |
| 25. Reverse Nodes in k-Group |
Solution |
Hard |
| 26. Remove Duplicates from Sorted Array |
Solution |
Easy |
| 28. Implement strStr() |
Solution |
Easy |
| 29. Divide Two Integers |
Solution |
Easy |
| 31. Next Permutation |
Solution |
Medium |
| 32. Longest Valid Parentheses |
Solution |
Hard |
| 33. Search in Rotated Sorted Array |
Solution |
Medium |
| 34. Search for a Range |
Solution |
Medium |
| 35. Search Insert Position |
Solution |
Easy |
| 36. Valid Sudoku |
Solution |
Medium |
| 37. Sudoku Solver |
Solution |
Hard |
| 39. Combination Sum |
Solution |
Medium |
| 41. First Missing Positive |
Solution |
Hard |
| 42. Trapping Rain Water |
Solution |
Hard |
| 44. Wildcard Matching |
Solution |
Hard |
| 45. Jump Game II |
Solution |
Hard |
| 46. Permutations |
Solution |
Medium |
| 47. Permutations II |
Solution |
Medium |
| 48. Rotate Image |
Solution |
Medium |
| 49. Group Anagrams |
Solution |
Medium |
| 50. Pow(x, n) |
Solution |
Medium |
| 51. N-Queens |
Solution |
Hard |
| 52. N-Queens II |
Solution |
Hard |
| 53. Maximum Subarray |
Solution |
Easy |
| 54. Spiral Matrix |
Solution |
Medium |
| 55. Jump Game |
Solution |
Medium |
| 56. Merge Intervals |
Solution |
Medium |
| 57. Insert Interval |
Solution |
Hard |
| 59. Spiral Matrix II |
Solution |
Medium |
| 60. Permutation Sequence |
Solution |
Medium |
| 61. Rotate List |
Solution |
Medium |
| 62. Unique Paths |
Solution |
Medium |
| 63. Unique Paths II |
Solution |
Medium |
| 64. Minimum Path Sum |
Solution |
Medium |
| 65. Valid Number |
Solution |
Hard |
| 66. Plus One |
Solution |
Easy |
| 67. Add Binary |
Solution |
Easy |
| 68. Text Justification |
Solution |
Hard |
| 69. Sqrt(x) |
Solution |
Easy |
| 70. Climbing Stairs |
Solution |
Easy |
| 71. Simplify Path |
Solution |
Medium |
| 72. Edit Distance |
Solution |
Hard |
| 73. Set Matrix Zeroes |
Solution |
Medium |
| 74. Search a 2D Matrix |
Solution |
Medium |
| 75. Sort Colors |
Solution |
Medium |
| 76. Minimum Window Substring |
Solution |
Hard |
| 78. Subsets |
Solution |
Medium |
| 79. Word Search |
Solution |
Medium |
| 80. Remove Duplicates from Sorted Array II |
Solution |
Medium |
| 81. Search in Rotated Sorted Array II |
Solution |
Medium |
| 82. Remove Duplicates from Sorted List II |
Solution |
Medium |
| 83. Remove Duplicates from Sorted List |
Solution |
Easy |
| 84. Largest Rectangle in Histogram |
Solution |
Hard |
| 85. Maximal Rectangle |
Solution |
Hard |
| 86. Partition List |
Solution |
Medium |
| 88. Merge Sorted Array |
Solution |
Easy |
| 90. Subsets II |
Solution |
Medium |
| 91. Decode Ways |
Solution |
Medium |
| 92. Reverse Linked List II |
Solution |
Medium |
| 93. Restore IP Addresses |
Solution |
Medium |
| 94. Binary Tree Inorder Traversal |
Solution |
Medium |
| 95. Unique Binary Search Trees II |
Solution |
Medium |
| 96. Unique Binary Search Trees |
Solution |
Medium |
| 97. Interleaving String |
Solution |
Hard |
| 98. Validate Binary Search Tree |
Solution |
Medium |
| 100. Same Tree |
Solution |
Easy |
| 101. Symmetric Tree |
Solution |
Easy |
| 102. Binary Tree Level Order Traversal |
Solution |
Medium |
| 103. Binary Tree Zigzag Level Order Traversal |
Solution |
Medium |
| 104. Maximum Depth of Binary Tree |
Solution |
Easy |
| 105. Construct Binary Tree from Preorder and Inorder Traversal |
Solution |
Medium |
| 106. Construct Binary Tree from Inorder and Postorder Traversal |
Solution |
Medium |
| 107. Binary Tree Level Order Traversal II |
Solution |
Easy |
| 108. Convert Sorted Array to Binary Search Tree |
Solution |
Easy |
| 109. Convert Sorted List to Binary Search Tree |
Solution |
Medium |
| 110. Balanced Binary Tree |
Solution |
Easy |
| 111. Minimum Depth of Binary Tree |
Solution |
Easy |
| 112. Path Sum |
Solution |
Easy |
| 113. Path Sum II |
Solution |
Medium |
| 114. Flatten Binary Tree to Linked List |
Solution |
Medium |
| 116. Populating Next Right Pointers in Each Node |
Solution |
Medium |
| 117. Populating Next Right Pointers in Each Node II |
Solution |
Medium |
| 119. Pascal's Triangle II |
Solution |
Easy |
| 120. Triangle |
Solution |
Medium |
| 121. Best Time to Buy and Sell Stock |
Solution |
Easy |
| 122. Best Time to Buy and Sell Stock II |
Solution |
Easy |
| 123. Best Time to Buy and Sell Stock III |
Solution |
Hard |
| 124. Binary Tree Maximum Path Sum |
Solution |
Hard |
| 125. Valid Palindrome |
Solution |
Easy |
| 126. Word Ladder II |
Solution |
Hard |
| 127. Word Ladder |
Solution |
Medium |
| 128. Longest Consecutive Sequence |
Solution |
Hard |
| 129. Sum Root to Leaf Numbers |
Solution |
Medium |
| 130. Surrounded Regions |
Solution |
Medium |
| 131. Palindrome Partitioning |
Solution |
Medium |
| 133. Clone Graph |
Solution |
Medium |
| 136. Single Number |
Solution |
Easy |
| 137. Single Number II |
Solution |
Medium |
| 138. Copy List with Random Pointer |
Solution |
Medium |
| 139. Word Break |
Solution |
Medium |
| 140. Word Break II |
Solution |
Hard |
| 141. Linked List Cycle |
Solution |
Easy |
| 142. Linked List Cycle II |
Solution |
Easy |
| 143. Reorder List |
Solution |
Medium |
| 144. Binary Tree Preorder Traversal |
Solution |
Medium |
| 146. LRU Cache |
Solution |
Hard |
| 147. Insertion Sort List |
Solution |
Medium |
| 148. Sort List |
Solution |
Medium |
| 149. Max Points on a Line |
Solution |
Hard |
| 150. Evaluate Reverse Polish Notation |
Solution |
Medium |
| 151. Reverse Words in a String |
Solution |
Medium |
| 152. Maximum Product Subarray |
Solution |
Medium |
| 153. Find Minimum in Rotated Sorted Array |
Solution |
Medium |
| 154. Find Minimum in Rotated Sorted Array II |
Solution |
Hard |
| 155. Min Stack |
Solution |
Easy |
| 157. Read N Characters Given Read4 |
Solution |
Easy |
| 158. Read N Characters Given Read4 II - Call multiple times |
Solution |
Hard |
| 159. Longest Substring with At Most Two Distinct Characters |
Solution |
Hard |
| 160. Intersection of Two Linked Lists |
Solution |
Easy |
| 161. One Edit Distance |
Solution |
Medium |
| 162. Find Peak Element |
Solution |
Medium |
| 163. Missing Ranges |
Solution |
Medium |
| 165. Compare Version Numbers |
Solution |
Medium |
| 166. Fraction to Recurring Decimal |
Solution |
Medium |
| 167. Two Sum II - Input array is sorted |
Solution |
Easy |
| 169. Majority Element |
Solution |
Easy |
| 173. Binary Search Tree Iterator |
Solution |
Medium |
| 179. Largest Number |
Solution |
Medium |
| 186. Reverse Words in a String II |
Solution |
Easy |
| 187. Repeated DNA Sequences |
Solution |
Medium |
| 188. Best Time to Buy and Sell Stock IV |
Solution |
Hard |
| 189. Rotate Array |
Solution |
Easy |
| 198. House Robber |
Solution |
Easy |
| 199. Binary Tree Right Side View |
Solution |
Medium |
| 200. Number of Islands |
Solution |
Medium |
| 201. Bitwise AND of Numbers Range |
Solution |
Medium |
| 202. Happy Number |
Solution |
Easy |
| 203. Remove Linked List Elements |
Solution |
Easy |
| 204. Count Primes |
Solution |
Easy |
| 205. Isomorphic Strings |
Solution |
Easy |
| 206. Reverse Linked List |
Solution |
Easy |
| 207. Course Schedule |
Solution |
Medium |
| 208. Implement Trie (Prefix Tree) |
Solution |
Medium |
| 209. Minimum Size Subarray Sum |
Solution |
Medium |
| 210. Course Schedule II |
Solution |
Medium |
| 211. Add and Search Word - Data structure design |
Solution |
Medium |
| 212. Word Search II |
Solution |
Hard |
| 213. House Robber II |
Solution |
Medium |
| 214. Shortest Palindrome |
Solution |
Medium |
| 215. Kth Largest Element in an Array |
Solution |
Medium |
| 216. Combination Sum III |
Solution |
Medium |
| 217. Contains Duplicate |
Solution |
Easy |
| 218. The Skyline Problem |
Solution |
Hard |
| 219. Contains Duplicate II |
Solution |
Easy |
| 220. Contains Duplicate III |
Solution |
Medium |
| 221. Maximal Square |
Solution |
Medium |
| 223. Rectangle Area |
Solution |
Medium |
| 224. Basic Calculator |
Solution |
Hard |
| 225. Implement Stack using Queues |
Solution |
Easy |
| 226. Invert Binary Tree |
Solution |
Easy |
| 227. Basic Calculator II |
Solution |
Medium |
| 228. Summary Ranges |
Solution |
Medium |
| 230. Kth Smallest Element in a BST |
Solution |
Medium |
| 231. Power of Two |
Solution |
Easy |
| 232. Implement Queue using Stacks |
Solution |
Easy |
| 233. Number of Digit One |
Solution |
Hard |
| 234. Palindrome Linked List |
Solution |
Easy |
| 235. Lowest Common Ancestor of a Binary Search Tree |
Solution |
Easy |
| 236. Lowest Common Ancestor of a Binary Tree |
Solution |
Medium |
| 237. Delete Node in a Linked List |
Solution |
Easy |
| 238. Product of Array Except Self |
Solution |
Medium |
| 239. Sliding Window Maximum |
Solution |
Hard |
| 240. Search a 2D Matrix II |
Solution |
Medium |
| 241. Different Ways to Add Parentheses |
Solution |
Medium |
| 242. Valid Anagram |
Solution |
Easy |
| 243. Shortest Word Distance |
Solution |
Easy |
| 246. Strobogrammatic Number |
Solution |
Easy |
| 247. Strobogrammatic Number II |
Solution |
Medium |
| 249. Group Shifted Strings |
Solution |
Medium |
| 251. Flatten 2D Vector |
Solution |
Medium |
| 252. Meeting Rooms |
Solution |
Easy |
| 253. Meeting Rooms II |
Solution |
Medium |
| 255. Verify Preorder Sequence in Binary Search Tree |
Solution |
Medium |
| 256. Paint House |
Solution |
Easy |
| 257. Binary Tree Paths |
Solution |
Easy |
| 259. 3Sum Smaller |
Solution |
Medium |
| 261. Graph Valid Tree |
Solution |
Medium |
| 263. Ugly Number |
Solution |
Easy |
| 264. Ugly Number II |
Solution |
Medium |
| 265. Paint House II |
Solution |
Hard |
| 267. Palindrome Permutation II |
Solution |
Medium |
| 268. Missing Number |
Solution |
Easy |
| 269. Alien Dictionary |
Solution |
Hard |
| 270. Closest Binary Search Tree Value |
Solution |
Easy |
| 271. Encode and Decode Strings |
Solution |
Medium |
| 272. Closest Binary Search Tree Value II |
Solution |
Medium |
| 273. Integer to English Words |
Solution |
Hard |
| 274. H-Index |
Solution |
Medium |
| 276. Paint Fence |
Solution |
Easy |
| 277. Find the Celebrity |
Solution |
Medium |
| 278. First Bad Version |
Solution |
Easy |
| 279. Perfect Squares |
Solution |
Medium |
| 280. Wiggle Sort |
Solution |
Medium |
| 281. Zigzag Iterator |
Solution |
Medium |
| 282. Expression Add Operators |
Solution |
Hard |
| 283. Move Zeroes |
Solution |
Easy |
| 284. Peeking Iterator |
Solution |
Medium |
| 285. Inorder Successor in BST |
Solution |
Medium |
| 286. Walls and Gates |
Solution |
Medium |
| 287. Find the Duplicate Number |
Solution |
Medium |
| 288. Unique Word Abbreviation |
Solution |
Medium |
| 289. Game of Life |
Solution |
Medium |
| 290. Word Pattern |
Solution |
Easy |
| 291. Word Pattern II |
Solution |
Hard |
| 293. Flip Game |
Solution |
Easy |
| 295. Find Median from Data Stream |
Solution |
Hard |
| 296. Best Meeting Point |
Solution |
Hard |
| 297. Serialize and Deserialize Binary Tree |
Solution |
Hard |
| 298. Binary Tree Longest Consecutive Sequence |
Solution |
Medium |
| 299. Bulls and Cows |
Solution |
Medium |
| 300. Longest Increasing Subsequence |
Solution |
Medium |
| 301. Remove Invalid Parentheses |
Solution |
Hard |
| 303. Range Sum Query - Immutable |
Solution |
Easy |
| 304. Range Sum Query 2D - Immutable |
Solution |
Medium |
| 305. Number of Islands II |
Solution |
Hard |
| 307. Range Sum Query - Mutable |
Solution |
Medium |
| 308. Range Sum Query 2D - Mutable |
Solution |
Hard |
| 309. Best Time to Buy and Sell Stock with Cooldown |
Solution |
Medium |
| 310. Minimum Height Trees |
Solution |
Medium |
| 311. Sparse Matrix Multiplication |
Solution |
Medium |
| 312. Burst Balloons |
Solution |
Hard |
| 313. Super Ugly Number |
Solution |
Medium |
| 314. Binary Tree Vertical Order Traversal |
Solution |
Medium |
| 315. Count of Smaller Numbers After Self |
Solution |
Hard |
| 317. Shortest Distance from All Buildings |
Solution |
Hard |
| 318. Maximum Product of Word Lengths |
Solution |
Medium |
| 320. Generalized Abbreviation |
Solution |
Medium |
| 322. Coin Change |
Solution |
Medium |
| 323. Number of Connected Components in an Undirected Graph |
Solution |
Medium |
| 324. Wiggle Sort II |
Solution |
Medium |
| 325. Maximum Size Subarray Sum Equals k |
Solution |
Medium |
| 327. Count of Range Sum |
Solution |
Hard |
| 328. Odd Even Linked List |
Solution |
Medium |
| 332. Reconstruct Itinerary |
Solution |
Medium |
| 333. Largest BST Subtree |
Solution |
Medium |
| 334. Increasing Triplet Subsequence |
Solution |
Medium |
| 336. Palindrome Pairs |
Solution |
Hard |
| 337. House Robber III |
Solution |
Medium |
| 338. Counting Bits |
Solution |
Medium |
| 339. Nested List Weight Sum |
Solution |
Easy |
| 340. Longest Substring with At Most K Distinct Characters |
Solution |
Hard |
| 341. Flatten Nested List Iterator |
Solution |
Medium |
| 343. Integer Break |
Solution |
Medium |
| 344. Reverse String |
Solution |
Easy |
| 345. Reverse Vowels of a String |
Solution |
Easy |
| 346. Moving Average from Data Stream |
Solution |
Easy |
| 347. Top K Frequent Elements |
Solution |
Medium |
| 348. Design Tic-Tac-Toe |
Solution |
Medium |
| 349. Intersection of Two Arrays |
Solution |
Easy |
| 350. Intersection of Two Arrays II |
Solution |
Easy |
| 351. Android Unlock Patterns |
Solution |
Medium |
| 352. Data Stream as Disjoint Intervals |
Solution |
Hard |
| 353. Design Snake Game |
Solution |
Medium |
| 354. Russian Doll Envelopes |
Solution |
Hard |
| 355. Design Twitter |
Solution |
Medium |
| 357. Count Numbers with Unique Digits |
Solution |
Medium |
| 358. Rearrange String k Distance Apart |
Solution |
Hard |
| 359. Logger Rate Limiter |
Solution |
Easy |
| 360. Sort Transformed Array |
Solution |
Medium |
| 361. Bomb Enemy |
Solution |
Medium |
| 362. Design Hit Counter |
Solution |
Medium |
| 363. Max Sum of Rectangle No Larger Than K |
Solution |
Hard |
| 365. Water and Jug Problem |
Solution |
Medium |
| 368. Largest Divisible Subset |
Solution |
Medium |
| 369. Plus One Linked List |
Solution |
Medium |
| 370. Range Addition |
Solution |
Medium |
| 373. Find K Pairs with Smallest Sums |
Solution |
Medium |
| 375. Guess Number Higher or Lower II |
Solution |
Medium |
| 377. Combination Sum IV |
Solution |
Medium |
| 378. Kth Smallest Element in a Sorted Matrix |
Solution |
Medium |
| 380. Insert Delete GetRandom O(1) |
Solution |
Medium |
| 382. Linked List Random Node |
Solution |
Medium |
| 383. Ransom Note |
Solution |
Easy |
| 384. Shuffle an Array |
Solution |
Medium |
| 386. Lexicographical Numbers |
Solution |
Medium |
| 387. First Unique Character in a String |
Solution |
Easy |
| 388. Longest Absolute File Path |
Solution |
Medium |
| 392. Is Subsequence |
Solution |
Medium |
| 393. UTF-8 Validation |
Solution |
Medium |
| 394. Decode String |
Solution |
Medium |
| 396. Rotate Function |
Solution |
Medium |
| 399. Evaluate Division |
Solution |
Medium |
| 403. Frog Jump |
Solution |
Hard |
| 405. Convert a Number to Hexadecimal |
Solution |
Easy |
| 406. Queue Reconstruction by Height |
Solution |
Medium |
| 407. Trapping Rain Water II |
Solution |
Medium |
| 408. Valid Word Abbreviation |
Solution |
Easy |
| 409. Longest Palindrome |
Solution |
Easy |
| 410. Split Array Largest Sum |
Solution |
Hard |
| 412. Fizz Buzz |
Solution |
Easy |
| 414. Third Maximum Number |
Solution |
Easy |
| 415. Add Strings |
Solution |
Easy |
| 416. Partition Equal Subset Sum |
Solution |
Medium |
| 417. Pacific Atlantic Water Flow |
Solution |
Medium |
| 418. Sentence Screen Fitting |
Solution |
Medium |
| 421. Maximum XOR of Two Numbers in an Array |
Solution |
Medium |
| 423. Reconstruct Original Digits from English |
Solution |
Medium |
| 424. Longest Repeating Character Replacement |
Solution |
Medium |
| 425. Word Squares |
Solution |
Hard |
| 427. Construct Quad Tree |
Solution |
Easy |
| 429. N-ary Tree Level Order Traversal |
Solution |
Easy |
| 432. All O`one Data Structure |
Solution |
Hard |
| 433. Minimum Genetic Mutation |
Solution |
Medium |
| 435. Non-overlapping Intervals |
Solution |
Medium |
| 437. Path Sum III |
Solution |
Easy |
| 438. Find All Anagrams in a String |
Solution |
Easy |
| 443. String Compression |
Solution |
Easy |
| 445. Add Two Numbers II |
Solution |
Medium |
| 448. Find All Numbers Disappeared in an Array |
Solution |
Easy |
| 449. Serialize and Deserialize BST |
Solution |
Medium |
| 450. Delete Node in a BST |
Solution |
Medium |
| 454. 4Sum II |
Solution |
Medium |
| 451. Sort Characters By Frequency |
Solution |
Medium |
| 459. Repeated Substring Pattern |
Solution |
Easy |
| 460. LFU Cache |
Solution |
Hard |
| 462. Minimum Moves to Equal Array Elements II |
Solution |
Medium |
| 463. Island Perimeter |
Solution |
Easy |
| 464. Can I Win |
Solution |
Medium |
| 465. Optimal Account Balancing |
Solution |
Hard |
| 472. Concatenated Words |
Solution |
Hard |
| 473. Matchsticks to Square |
Solution |
Medium |
| 474. Ones and Zeroes |
Solution |
Medium |
| 477. Total Hamming Distance |
Solution |
Medium |
| 480. Sliding Window Median |
Solution |
Hard |
| 481. Magical String |
Solution |
Medium |
| 482. License Key Formatting |
Solution |
Easy |
| 485. Max Consecutive Ones |
Solution |
Easy |
| 486. Predict the Winner |
Solution |
Medium |
| 487. Max Consecutive Ones II |
Solution |
Medium |
| 490. The Maze |
Solution |
Medium |
| 491. Increasing Subsequences |
Solution |
Medium |
| 494. Target Sum |
Solution |
Medium |
| 496. Next Greater Element I |
Solution |
Easy |
| 498. Diagonal Traverse |
Solution |
Medium |
| 499. The Maze III |
Solution |
Hard |
| 503. Next Greater Element II |
Solution |
Medium |
| 505. The Maze II |
Solution |
Hard |
| 508. Most Frequent Subtree Sum |
Solution |
Medium |
| 513. Find Bottom Left Tree Value |
Solution |
Medium |
| 515. Find Largest Value in Each Tree Row |
Solution |
Medium |
| 516. Longest Palindromic Subsequence |
Solution |
Medium |
| 518. Coin Change 2 |
Solution |
Medium |
| 519. Random Flip Matrix |
Solution |
Medium |
| 523. Continuous Subarray Sum |
Solution |
Medium |
| 525. Contiguous Array |
Solution |
Medium |
| 527. Word Abbreviation |
Solution |
Hard |
| 529. Minesweeper |
Solution |
Medium |
| 530. Minimum Absolute Difference in BST |
Solution |
Easy |
| 531. Lonely Pixel I |
Solution |
Medium |
| 535. Encode and Decode TinyURL |
Solution |
Medium |
| 536. Construct Binary Tree from String |
Solution |
Medium |
| 538. Convert BST to Greater Tree |
Solution |
Easy |
| 540. Single Element in a Sorted Array |
Solution |
Medium |
| 541. Reverse String II |
Solution |
Easy |
| 542. 01 Matrix |
Solution |
Medium |
| 543. Diameter of Binary Tree |
Solution |
Easy |
| 544. Output Contest Matches |
Solution |
Medium |
| 545. Boundary of Binary Tree |
Solution |
Medium |
| 547. Friend Circles |
Solution |
Medium |
| 554. Brick Wall |
Solution |
Medium |
| 556. Next Greater Element III |
Solution |
Medium |
| 557. Reverse Words in a String III |
Solution |
Easy |
| 558. Quad Tree Intersection |
Solution |
Easy |
| 560. Subarray Sum Equals K |
Solution |
Medium |
| 567. Permutation in String |
Solution |
Easy |
| 568. Maximum Vacation Days |
Solution |
Hard |
| 572. Subtree of Another Tree |
Solution |
Easy |
| 582. Kill Process |
Solution |
Medium |
| 588. Design In-Memory File System |
Solution |
Hard |
| 590. N-ary Tree Postorder Traversal |
Solution |
Easy |
| 594. Longest Harmonious Subsequence |
Solution |
Easy |
| 604. Design Compressed String Iterator |
Solution |
Easy |
| 611. Valid Triangle Number |
Solution |
Medium |
| 616. Add Bold Tag in String |
Solution |
Medium |
| 621. Task Scheduler |
Solution |
Medium |
| 622. Design Circular Queue |
Solution |
Medium |
| 623. Add One Row to Tree |
Solution |
Medium |
| 628. Maximum Product of Three Numbers |
Solution |
Easy |
| 632. Smallest Range |
Solution |
Hard |
| 633. Sum of Square Numbers |
Solution |
Easy |
| 635. Design Log Storage System |
Solution |
Hard |
| 636. Exclusive Time of Functions |
Solution |
Medium |
| 637. Average of Levels in Binary Tree |
Solution |
Easy |
| 639. Decode Ways II |
Solution |
Hard |
| 640. Solve the Equation |
Solution |
Medium |
| 641. Design Circular Deque |
Solution |
Medium |
| 642. Design Search Autocomplete System |
Solution |
Hard |
| 643. Maximum Average Subarray I |
Solution |
Easy |
| 646. Maximum Length of Pair Chain |
Solution |
Medium |
| 647. Palindromic Substrings |
Solution |
Medium |
| 648. Replace Words |
Solution |
Medium |
| 652. Find Duplicate Subtrees |
Solution |
Medium |
| 653. Two Sum IV - Input is a BST |
Solution |
Easy |
| 654. Maximum Binary Tree |
Solution |
Medium |
| 657. Judge Route Circle |
Solution |
Easy |
| 658. Find K Closest Elements |
Solution |
Medium |
| 659. Split Array into Consecutive Subsequences |
Solution |
Medium |
| 661. Image Smoother |
Solution |
Easy |
| 662. Maximum Width of Binary Tree |
Solution |
Medium |
| 663. Equal Tree Partition |
Solution |
Medium |
| 665. Non-decreasing Array |
Solution |
Easy |
| 669. Trim a Binary Search Tree |
Solution |
Easy |
| 671. Second Minimum Node In a Binary Tree |
Solution |
Easy |
| 673. Number of Longest Increasing Subsequence |
Solution |
Medium |
| 674. Longest Continuous Increasing Subsequence |
Solution |
Easy |
| 675. Cut Off Trees for Golf Event |
Solution |
Hard |
| 676. Implement Magic Dictionary |
Solution |
Medium |
| 677. Map Sum Pairs |
Solution |
Medium |
| 678. Valid Parenthesis String |
Solution |
Medium |
| 680. Valid Palindrome II |
Solution |
Easy |
| 681. Next Closest Time |
Solution |
Medium |
| 682. Baseball Game |
Solution |
Easy |
| 683. K Empty Slots |
Solution |
Hard |
| 684. Redundant Connection |
Solution |
Medium |
| 685. Redundant Connection II |
Solution |
Hard |
| 686. Repeated String Match |
Solution |
Easy |
| 687. Longest Univalue Path |
Solution |
Easy |
| 689. Maximum Sum of 3 Non-Overlapping Subarrays |
Solution |
Hard |
| 692. Top K Frequent Words |
Solution |
Medium |
| 695. Max Area of Island |
Solution |
Medium |
| 698. Partition to K Equal Sum Subsets |
Solution |
Medium |
| 702. Search in a Sorted Array of Unknown Size |
Solution |
Medium |
| 705. Design HashSet |
Solution |
Easy |
| 706. Design HashMap |
Solution |
Easy |
| 707. Design Linked List |
Solution |
Easy |
| 709. To Lower Case |
Solution |
Easy |
| 712. Minimum ASCII Delete Sum for Two Strings |
Solution |
Medium |
| 713. Subarray Product Less Than K |
Solution |
Medium |
| 714. Best Time to Buy and Sell Stock with Transaction Fee |
Solution |
Medium |
| 715. Range Module |
Solution |
Hard |
| 716. Max Stack |
Solution |
Hard |
| 718. Maximum Length of Repeated Subarray |
Solution |
Medium |
| 719. Find K-th Smallest Pair Distance |
Solution |
Hard |
| 720. Longest Word in Dictionary |
Solution |
Easy |
| 721. Accounts Merge |
Solution |
Medium |
| 727. Minimum Window Subsequence |
Solution |
Hard |
| 729. My Calendar I |
Solution |
Medium |
| 731. My Calendar II |
Solution |
Medium |
| 734. Sentence Similarity |
Solution |
Easy |
| 737. Sentence Similarity II |
Solution |
Medium |
| 738. Monotone Increasing Digits |
Solution |
Medium |
| 739. Daily Temperatures |
Solution |
Medium |
| 740. Delete and Earn |
Solution |
Medium |
| 746. Min Cost Climbing Stairs |
Solution |
Easy |
| 748. Shortest Completing Word |
Solution |
Medium |
| 750. Number Of Corner Rectangles |
Solution |
Medium |
| 752. Open the Lock |
Solution |
Medium |
| 759. Employee Free Time |
Solution |
Hard |
| 760. Find Anagram Mappings |
Solution |
Easy |
| 763. Partition Labels |
Solution |
Medium |
| 765. Couples Holding Hands |
Solution |
Hard |
| 767. Reorganize String |
Solution |
Medium |
| 768. Max Chunks To Make Sorted II |
Solution |
Hard |
| 769. Max Chunks To Make Sorted |
Solution |
Medium |
| 771. Jewels and Stones |
Solution |
Easy |
| 777. Swap Adjacent in LR String |
Solution |
Medium |
| 779. K-th Symbol in Grammar |
Solution |
Medium |
| 785. Is Graph Bipartite? |
Solution |
Medium |
| 787. Cheapest Flights Within K Stops |
Solution |
Medium |
| 790. Domino and Tromino Tiling |
Solution |
Medium |
| 792. Number of Matching Subsequences |
Solution |
Medium |
| 797. All Paths From Source to Target |
Solution |
Medium |
| 783. Minimum Distance Between BST Nodes |
Solution |
Easy |
| 802. Find Eventual Safe States |
Solution |
Medium |
| 803. Bricks Falling When Hit |
Solution |
Hard |
| 804. Unique Morse Code Words |
Solution |
Easy |
| 807. Max Increase to Keep City Skyline |
Solution |
Medium |
| 819. Most Common Word |
Solution |
Easy |
| 826. Most Profit Assigning Work |
Solution |
Medium |
| 832. Flipping an Image |
Solution |
Easy |
| 836. Rectangle Overlap |
Solution |
Easy |
| 841. Keys and Rooms |
Solution |
Medium |
| 842. Split Array into Fibonacci Sequence |
Solution |
Medium |
| 843. Guess the Word |
Solution |
Hard |
| 844. Backspace String Compare |
Solution |
Easy |
| 845. Longest Mountain in Array |
Solution |
Medium |
| 846. Hand of Straights |
Solution |
Medium |
| 849. Maximize Distance to Closest Person |
Solution |
Easy |
| 850. Rectangle Area II |
Solution |
Hard |
| 855. Exam Room |
Solution |
Medium |
| 859. Buddy Strings |
Solution |
Easy |
| 860. Lemonade Change |
Solution |
Easy |
| 862. Shortest Subarray with Sum at Least K |
Solution |
Hard |
| 863. All Nodes Distance K in Binary Tree |
Solution |
Medium |
| 864. Shortest Path to Get All Keys |
Solution |
Hard |
| 873. Length of Longest Fibonacci Subsequence |
Solution |
Medium |
| 875. Koko Eating Bananas |
Solution |
Easy |
| 876. Middle of the Linked List |
Solution |
Easy |
| 877. Stone Game |
Solution |
Medium |
| 879. Profitable Schemes |
Solution |
Hard |
| 884. Decoded String at Index |
Solution |
Medium |
| 885. Boats to Save People |
Solution |
Medium |
| 886. Possible Bipartition |
Solution |
Medium |
| 887. Projection Area of 3D Shapes |
Solution |
Easy |
| 890. Find and Replace Pattern |
Solution |
Medium |
| 895. Maximum Frequency Stack |
Solution |
Hard |
| Convert Binary Search Tree to Sorted Doubly Linked List |
Solution |
- |
| HighestPopulationYear |
Solution |
- |
| Insert into a Cyclic Sorted List |
Solution |
- |
| Robot Room Cleaner |
Solution |
- |
| AsyncJobMonitor |
Solution |
- |
| Bench |
Solution |
- |
| FindCenterOfMassInA2DArray |
Solution |
- |
| OneEditDistance |
Solution |
- |
| CollatzConjecture |
Solution |
- |
| Subsequence |
Solution |
- |
| TreeToForestByErasingNodes |
Solution |
- |
| KMP |
Solution |
- |