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 |