Authored by Tony Feng
Created on Oct 1st, 2022
Last Modified on Oct 31st, 2022
Intro
Blind 75 leetcode is a list of 75 most frequent asked leetcode questions which had helped many developers clear interviews of Google, Facebook, Amazon etc. Hence, it is a tried and tested list with 1000s of testimonials available on all public review platforms such as quora, teamblind etc.
Table of Questions
Arrays & Hashing
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 01 | 217. Contains Duplicate | Easy | 10-17-2022 | Video |
| 02 | 242. Valid Anagram | Easy | 10-17-2022 | Video |
| 03 | 1. Two Sum | Easy | 10-17-2022 | Video |
| 04 | 49. Group Anagrams | Medium | 10-17-2022 | Video |
| 05 | 347. Top K Frequent Elements | Medium | 10-17-2022 | Video |
| 06 | 238. Product of Array Except Self | Medium | 10-17-2022 | Video |
| 07 | 271. Encode and Decode Strings | Medium | 10-17-2022 | Video |
| 08 | 128. Longest Consecutive Sequence | Medium | 10-17-2022 | Video |
Two Pointers
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 09 | 125. Valid Palindrome | Easy | 10-18-2022 | Video |
| 10 | 15. 3Sum | Medium | 10-18-2022 | Video |
| 11 | 11. Container With Most Water | Medium | 10-18-2022 | Video |
Sliding Window
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 12 | 121. Best Time to Buy and Sell Stock | Easy | 10-18-2022 | Video |
| 13 | 3. Longest Substring Without Repeating Characters | Medium | 10-18-2022 | Video |
| 14 | 424. Longest Repeating Character Replacement | Medium | 10-18-2022 | Video |
| 15 | 76. Minimum Window Substring | Hard | 10-19-2022 | Video |
Stack
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 16 | 20. Valid Parentheses | Easy | 10-19-2022 | Video |
Binary Search
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 17 | 33. Search in Rotated Sorted Array | Medium | 10-19-2022 | Video |
| 18 | 153. Find Minimum in Rotated Sorted Array | Medium | 10-19-2022 | Video |
Linked List
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 19 | 206. Reverse Linked List | Easy | 10-20-2022 | Video |
| 20 | 21. Merge Two Sorted Lists | Easy | 10-20-2022 | Video |
| 21 | 143. Reorder List | Medium | 10-20-2022 | Video |
| 22 | 19. Remove Nth Node From End of List | Medium | 10-20-2022 | Video |
| 23 | 141. Linked List Cycle | Easy | 10-20-2022 | Video |
| 24 | 23. Merge k Sorted Lists | Hard | 10-20-2022 | Video |
Trees
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 25 | 226. Invert Binary Tree | Easy | 10-21-2022 | Video |
| 26 | 104. Maximum Depth of Binary Tree | Easy | 10-21-2022 | Video |
| 27 | 100. Same Tree | Easy | 10-21-2022 | Video |
| 28 | 572. Subtree of Another Tree | Easy | 10-21-2022 | Video |
| 29 | 235. Lowest Common Ancestor of a Binary Search Tree | Medium | 10-21-2022 | Video |
| 30 | 102. Binary Tree Level Order Traversal | Medium | 10-22-2022 | Video |
| 31 | 98. Validate Binary Search Tree | Medium | 10-22-2022 | Video |
| 32 | 230. Kth Smallest Element in a BST | Medium | 10-22-2022 | Video |
| 33 | 105. Construct Binary Tree from Preorder and Inorder Traversal | Medium | 10-22-2022 | Video |
| 34 | 124. Binary Tree Maximum Path Sum | Hard | 10-22-2022 | Video |
| 35 | 297. Serialize and Deserialize Binary Tree | Hard | 10-22-2022 | Video |
Tries
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 36 | 208. Implement Trie (Prefix Tree) | Medium | 10-25-2022 | Video |
| 37 | 211. Design Add and Search Words Data Structure | Medium | 10-25-2022 | Video |
| 38 | 212. Word Search II | Hard | 10-25-2022 | Video |
Heap & Priority Queue
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 39 | 295. Find Median from Data Stream | Hard | 10-23-2022 | Video |
Backtracking
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 40 | 39. Combination Sum | Medium | 10-24-2022 | Video |
| 41 | 79. Word Search | Medium | 10-24-2022 | Video |
Graphs
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 42 | 200. Number of Islands | Medium | 10-24-2022 | Video |
| 43 | 133. Clone Graph | Medium | 10-25-2022 | Video |
| 44 | 417. Pacific Atlantic Water Flow | Medium | 10-31-2022 | Video |
| 45 | 207. Course Schedule | Medium | 10-31-2022 | Video |
| 46 | 323. # of Connected Nodes in an Undirected Graph | Medium | 10-31-2022 | Video |
| 47 | 261. Graph Valid Tree | Medium | 10-31-2022 | Video |
Advanced Graphs
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 48 | 269. Alien Dictionary | Hard | 10-28-2022 | Video |
1-D Dynamic Programming
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 49 | 70. Climbing Stairs | Easy | 10-26-2022 | Video |
| 50 | 198. House Robber | Medium | 10-26-2022 | Video |
| 51 | 213. House Robber II | Medium | 10-26-2022 | Video |
| 52 | 5. Longest Palindromic Substring | Medium | 10-26-2022 | Video |
| 53 | 647. Palindromic Substrings | Medium | 10-26-2022 | Video |
| 54 | 91. Decode Ways | Medium | 10-27-2022 | Video |
| 55 | 322. Coin Change | Medium | 10-27-2022 | Video |
| 56 | 152. Maximum Product Subarray | Medium | 10-27-2022 | Video |
| 57 | 139. Word Break | Medium | 10-27-2022 | Video |
| 58 | 300. Longest Increasing Subsequence | Medium | 10-27-2022 | Video |
2-D Dynamic Programming
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 59 | 62. Unique Paths | Medium | 10-28-2022 | Video |
| 60 | 1143. Longest Common Subsequence | Medium | 10-28-2022 | Video |
Greedy
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 61 | 53. Maximum Subarray | Medium | 10-28-2022 | Video |
| 62 | 55. Jump Game | Medium | 10-28-2022 | Video |
Intervals
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 63 | 57. Insert Interval | Medium | 11-01-2022 | Video |
| 64 | 56. Merge Intervals | Medium | 11-01-2022 | Video |
| 65 | 435. Non-overlapping Intervals | Medium | 11-01-2022 | Video |
| 66 | 252. Meeting Rooms | Easy | 11-01-2022 | Video |
| 67 | 253. Meeting Rooms II | Medium | 11-01-2022 | Video |
Math & Geometry
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 68 | 48. Rotate Image | Medium | 11-02-2022 | Video |
| 69 | 54. Spiral Matrix | Medium | 11-02-2022 | Video |
| 70 | 73. Set Matrix Zeroes | Medium | 11-02-2022 | Video |
Bit Manipulation
| ID | Question | Level | Update Date | Video |
|---|---|---|---|---|
| 71 | 191. Number of 1 Bits | Easy | 11-03-2022 | Video |
| 72 | 338. Counting Bits | Easy | 11-03-2022 | Video |
| 73 | 190. Reverse Bits | Easy | 11-03-2022 | Video |
| 74 | 268. Missing Number | Easy | 11-03-2022 | Video |
| 75 | 371. Sum of Two Integers | Medium | 11-03-2022 | Video |