1. Two Sum
2. Symmetric Tree
3. Implement Queue using Stacks
4. Valid Parentheses
5. Reverse Words in a String III
6. Invert Binary Tree
7. Check If a Number Is Majority Element in a Sorted Array
8. Intersection of Two Arrays II
9. Height Checker
10. Find Pivot Index
11. Remove Duplicates from Sorted List
12. K-diff Pairs in an Array
13. Isomorphic Strings
14. Fizz Buzz
15. Design HashMap
16. Maximum Subarray
17. Largest Number
18. Reverse Words in a String
19. Course Schedule
20. Find the Duplicate Number
21. Group Anagrams
22. Add and Search Word - Data structure design
23. Find Minimum in Rotated Sorted Array
24. Flatten 2D Vector
25. Decode String
26. Letter Combinations of a Phone Number
27. Set Matrix Zeroes
28. Find the Smallest Divisor Given a Threshold
29. Insert Delete GetRandom O(1)
30. Valid Sudoku
31. Merge Intervals
32. Longest Increasing Subsequence
33. Design Tic-Tac-Toe
34. Remove Duplicates from Sorted List II
35. Word Ladder
36. Product of Array Except Self
37. Word Break
38. Search in Rotated Sorted Array
39. Lowest Common Ancestor of a Binary Tree
40. Permutations
41. Add Two Numbers
42. Design Snake Game
43. Longest Substring Without Repeating Characters
44. Validate Binary Search Tree
45. 3Sum
46. LRU Cache
47. Simplify Path
48. Integer to Roman
49. Number of Islands
50. Friend Circles
51. Kth Largest Element in an Array
52. Search a 2D Matrix II
53. Top K Frequent Words
54. Generate Parentheses
55. Shuffle an Array
56. Binary Tree Vertical Order Traversal
57. Rotate Image
58. Candy
59. Find Median from Data Stream
60. Minimum Window Substring
61. The Skyline Problem
62. LFU Cache
63. Serialize and Deserialize Binary Tree
64. Design Search Autocomplete System
65. Trapping Rain Water
66. Maximum Frequency Stack
67. First Missing Positive
68. Word Search II
69. Reaching Points
70. Merge k Sorted Lists