Amazon

 Important Questions:

1. Two Sum
2. Add Two Numbers
3. Longest Substring Without Repeating Characters
4. Longest Palindromic Substring
5. String to Integer (atoi)
6. 3Sum
7. Letter Combinations of a Phone Number
8. Valid Parentheses
9. Merge Two Sorted Lists
10. Merge k Sorted Lists
11. Trapping Rain Water
12. Rotate Image
13. Group Anagrams
14. Set Matrix Zeroes
15. Subsets
16. Gray Code
17. Validate Binary Search Tree
18. Binary Tree Level Order Traversal
19. Pascal’s Triangle II
20. Best Time to Buy and Sell Stock
21. Word Ladder II
22. Word Ladder
23. Copy List with Random Pointer
24. Word Break
25. Linked List Cycle
26. LRU Cache
27. Min Stack
28. Intersection of Two Linked Lists
29. Two Sum II - Input Array Is Sorted
30. Rotate Array
31. Binary Tree Right Side View
32. Number of Islands
33. Count Primes
34. Reverse Linked List
35. Kth Largest Element in an Array
36. Palindrome Linked List
37. Lowest Common Ancestor of a Binary Search Tree
38. Lowest Common Ancestor of a Binary Tree
39. Product of Array Except Self
40. Sliding Window Maximum
41. Search a 2D Matrix II
42. Valid Anagram
43. Serialize and Deserialize Binary Tree
44. Design Twitter
45. Insert Delete GetRandom O(1)
46. First Unique Character in a String
47. Rotate Function
48. Third Maximum Number
49. Find All Anagrams in a String
50. Serialize and Deserialize BST
51. Sort Characters By Frequency
52. Repeated Substring Pattern
53. LFU Cache
54. Most Frequent Subtree Sum
55. Longest Palindromic Subsequence
56. Super Washing Machines
57. Minesweeper
58. K-diff Pairs in an Array
59. Encode and Decode TinyURL
60. Complex Number Multiplication
61. Convert BST to Greater Tree
62. Optimal Division
63. Construct String from Binary Tree
64. Merge Two Binary Trees
65. Solve the Equation
66. Set Mismatch
67. Maximum Length of Pair Chain
68. Image Smoother
69. Maximum Width of Binary Tree
70. Cut Off Trees for Golf Event
71. Baseball Game
72. Top K Frequent Words
73. Split Linked List in Parts