| 1. Two sum up |
Code |
O(N) |
O(N) |
Easy |
| 2. Add two numbers |
Code |
O(N+M) |
O(1) |
Medium |
| 3. Longest Substring Without Repeating Characters |
Code |
O(N) |
O(1) |
Medium |
| 4. Median of Two Sorted Arrays |
Code |
O(log(n+m)) |
O(log(n+m)) |
Hard |
| 5. Longest Palindromic Substring |
Code |
O(N^2) |
O(1) |
Medium |
| 7. Reverse Integer |
Code |
O(1) |
O(1) |
Easy |
| 10. Regular Expression Matching |
Code |
O(NM) |
O(NM) |
Hard |
| 11. Container With Most Water |
Code |
O(N) |
O(1) |
Medium |
| 15. 3Sum |
Code |
O(N^2) |
O(N^2) |
Medium |
| 17. Letter Combinations of a Phone Number |
Code |
O(N) |
O(N) |
Medium |
| 19. Remove Nth Node From End of List |
Code |
O(N) |
O(1) |
Medium |
| 20. Valid Parantheses |
Code |
O(N) |
O(1) |
Easy |
| 21. Merge Two Sorted Lists |
Code |
O(N+M) |
O(N+M) |
Easy |
| 22. Generate Parentheses |
Code |
O(2^N?) |
O(2^N?) |
Medium |
| 23. Merge k Sorted Lists |
Code |
O(NlogK) |
O(NK) |
Hard |
| 24. Swap Nodes in Pairs |
Code |
O(N) |
O(N) |
Medium |
| 25. Reverse Nodes in k-Group |
Code |
O(N) |
O(N) |
Hard |
| 26. Remove Duplicates from Sorted Array |
Code |
O(N) |
O(1) |
Easy |
| 29. Divide Two Integers |
Code |
O() |
O() |
__ |
| 31. Next Permutation |
Code |
O(N) |
O(1) |
Medium |
| 32. Longest Valid Parantheses |
Code |
O() |
O() |
__ |
| 33. Search in Rotated Sorted Array |
Code |
O() |
O() |
__ |
| 34. Search for a Range |
Code |
O() |
O() |
__ |
| 36. Valid Sudoku |
Code |
O() |
O() |
__ |
| 37. Sudoku Solver |
Code |
O(?) |
O(?) |
Hard |
| 41. First Missing Positive |
Code |
O() |
O() |
__ |
| 42. Trapping Rain Water |
Code |
O(N) |
O(N) |
Hard |
| 44. Wildcard Matching |
Code |
O(NM) |
O(NM) |
Hard |
| 45. Jump Game II |
Code |
O(N) |
O(1) |
Hard |
| 49. Group Anagrams |
Code |
O(NMlogM) |
O(NM) |
Medium |
| 50. Pow(x,n) |
Code |
O() |
O() |
__ |
| 51. N-Queens |
Code |
O(N!) |
O(N!) |
Hard |
| 52. N-Queens II |
Code |
O(N^N) |
O(N) |
Hard |
| 55. Jump Game |
Code |
O(N) |
O(1) |
Medium |
| 56. Merge Intervals |
Code |
O(Nlog(N)) |
O(N) |
Medium |
| 66. Unique Paths |
Code |
O(MN) |
O(MN) |
Medium |
| 72. Edit Distance |
Code |
O(MN) |
O(MN) |
Hard |
| 75. Sort Colors |
Code |
O(N) |
O(1) |
Medium |
| 76. Minimum Window Substring |
Code |
O(N) |
O(1) |
Hard |
| 79. Word Search |
Code |
O(NMK) |
O(N^2) |
Medium |
| 84. Largest Rectangle in Histogram |
Code |
O(N), O(Nlog(N)) |
O(N) |
Hard |
| 88. Merge Sorted Array |
Code |
O(N+M) |
O(1) |
Easy |
| 91. Decode Ways |
Code |
O(N) |
O(N) |
Medium |
| 94. Binary Tree Inorder Traversal |
Code |
O(N) |
O(N) |
Medium |
| 98. Validate Binary Search Tree |
Code |
O(N) |
O(1) |
Medium |
| 102. Binary Tree Level Order Traversal |
Code |
O(N) |
O(N) |
Medium |
| 103. Binary Tree Zigzag Level Order Traversal |
Code |
O(N) |
O(N) |
Medium |
| 116. Populating Next Right Pointers in Each Node |
Code |
O(N) |
O(1) |
Medium |
| 124. Binary Tree Maximum Path Sum |
Code |
O(N) |
O(N) |
Hard |
| 127. Word Ladder |
Code |
O(M) |
O(M) |
Medium |
| 128. Longest Consecutive Sequence |
Code |
O(N) |
O(N) |
Hard |
| 132. Palindrome Partitioning II |
Code |
O(N^2) |
O(N^2) |
Hard |
| 139. Word Break |
Code |
O(N^2+M) |
O(N+M) |
Medium |
| 140. Word Break II |
Code |
O(N^2*log(M)) |
O(N^2+M) |
Hard |
| 145. Binary Tree Postorder Traversal |
Code |
O(N) |
O(N) |
Hard |
| 146. LRU Cache |
Code |
O(1), O(1) |
O(1), O(1) |
Hard |
| 149. Max Points on a Line |
Code |
O(N^2log(N)) |
O(N) |
Hard |
| 153. Find Minimum in Rotated Sorted Array |
Code |
O(log(N)) |
O(1) |
Medium |
| 154. Find Minimum in Rotated Sorted Array II |
Code |
O(N) |
O(1) |
Hard |
| 162. Find Peak Element |
Code |
O(log N) |
O(log N) |
Medium |
| 174. Dungeon Game |
Code |
O(NM) |
O(M) |
Hard |
| 179. Largest Number |
Code |
O(NlogN) |
O(1) |
Medium |
| 200. Number of Islands |
Code |
O(NM) |
O(NM) |
Medium |
| 207. Course Schedule |
Code |
O(N+M) |
O(N+M) |
Medium |
| 208. Implement Trie (Prefix Tree) |
Code |
O() |
O() |
Medium |
| 210. Course Schedule II |
Code |
O(N+M) |
O(N+M) |
Medium |
| 212. Word Search II |
Code |
O(NM+K) |
O(NM+K) |
Hard |
| 236. Lowest Common Ancestor of a Binary Tree |
Code |
O(N) |
O(N) |
Medium |
| 239. Sliding Window Maximum |
Code |
O(N) |
O(K) |
Hard |
| 295. Find Median from Data Stream |
Code |
O(logN), O(1) |
O(1), O(1) |
Hard |
| 297. Serialize and Deserialize Binary Tree |
Code |
O(N), O(N^2) |
O(N), O(N) |
Hard |
| 301. Remove Invalid Parentheses |
Code |
O(?) |
O(?) |
Hard |
| 310. Minimum Height Trees |
Code |
O(N) |
O(N) |
Medium |
| 312. Burst Balloons |
Code |
O(N^3) |
O(N^2) |
Hard |
| 315. Count of Smaller Numbers After Self |
Code |
O(Nlog(N)) |
O(Nlog(N)) |
Hard |
| 322. Coin Change |
Code |
O(NM) |
O(M) |
Medium |
| 329. Longest Increasing Path in a Matrix |
Code |
O(NM) |
O(NM) |
Hard |
| 336. Palindrome Pairs |
Code |
O(NK^2) |
O(NK) |
Hard |
| 347. Top K Frequent Elements |
Code |
O(Nlog(K)) |
O(N) |
Medium |
| 352. Data Stream as Disjoint Intervals |
Code |
O(log(N)) |
O(N) |
Hard |
| 354. Russian Doll Envelopes |
Code |
O(Nlog(N)) |
O(N) |
Hard |
| 378. Kth Smallest Element in a Sorted Matrix |
Code |
O(N*(max-min)) |
O(1) |
Medium |
| 395. Longest Substring with At Least K Repeating Characters |
Code |
O(N) |
O(1) |
Medium |
| 403. Frog Jump |
Code |
O(N^2) |
O(N) |
Hard |
| 407. Trapping Rain Water II |
Code |
O(N^2 M) |
O(NM) |
Hard |
| 410. Split Array Largest Sum |
Code |
O(N^2M) |
O(NM) |
Hard |
| 446. Arithmetic Slices II - Subsequence |
Code |
O(N^2) |
O(N^2) |
Hard |
| 460. LFU Cache |
Code |
O(1), O(1) |
O(1), O(1) |
Hard |
| 493. Reverse Pairs |
Code |
O(Nlog(N)) |
O(Nlog(N)) |
Hard |
| 629. K Inverse Pairs Array |
Code |
O(NK) |
O(NK) |
Hard |
| 630. Course Schedule III |
Code |
O(Nlog(N)) |
O(N) |
Hard |
| 632. Smallest Range |
Code |
O(K*N) |
O(K) |
Hard |
| 668. Kth Smallest Number in Multiplication Table |
Code |
O(Nlog(max-min)) |
O(1) |
Hard |
| 689. Maximum Sum of 3 Non-Overlapping Subarrays |
Code |
O(N) |
O(N) |
Hard |
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