Blind 75 + Amazon top 50 Flashcards
Memorize the best questions (108 cards)
1
Q
1.Two Sum
A
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2
Q
2.Longest Substring Without Repeating Characters
A
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3
Q
3.Longest Palindromic Substring
A
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4
Q
4.Container With Most Water
A
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5
Q
5.3Sum
A
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6
Q
6.Remove Nth Node From End of List
A
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7
Q
7.Valid Parentheses
A
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8
Q
8.Merge Two Sorted Lists
A
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9
Q
9.Merge k Sorted Lists
A
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10
Q
10.Search in Rotated Sorted Array
A
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11
Q
11.Combination Sum
A
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12
Q
12.Trapping Rain Water
A
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13
Q
13.Rotate Image
A
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14
Q
14.Group Anagrams
A
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15
Q
15.Maximum Subarray
A
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16
Q
16.Spiral Matrix
A
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17
Q
17.Jump Game
A
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18
Q
18.Merge Intervals
A
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19
Q
19.Insert Interval
A
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20
Q
20.Unique Paths
A
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21
Q
21.Climbing Stairs
A
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22
Q
22.Set Matrix Zeroes
A
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23
Q
23.Minimum Window Substring
A
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24
Q
24.Word Search
A
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25
25. Decode Ways
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26
26. Validate Binary Search Tree
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27
27. Recover Binary Search Tree
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28
28. Same Tree
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29
29. Binary Tree Level Order Traversal
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30
30. Maximum Depth of Binary Tree
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31
31. Construct Binary Tree from Preorder and Inorder Traversal
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32
32. Best Time to Buy and Sell Stock
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33
33. Binary Tree Maximum Path Sum
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34
34. Valid Palindrome
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35
35. Word Ladder II
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36
36. Word Ladder
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37
37. Longest Consecutive Sequence
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38
38. Clone Graph
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39
39. Copy List with Random Pointer
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40
40. Word Break
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41
41. Word Break II
Time complexity is legit
42
42. Linked List Cycle
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43
43. Reorder List
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44
44. LRU Cache
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45
45. Maximum Product Subarray
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46
46. Find Minimum in Rotated Sorted Array
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47
47. Min Stack
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48
48. Reverse Bits
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49
49. Number of 1 Bits
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50
50. House Robber
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51
51. Number of Islands*********
TODO: UNION FIND
If you don't want to modify array, use visited set. If don't want extra space, make the visited on the grid to '0' or '#'
52
52. Reverse Linked List
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53
53. Course Schedule
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54
54. Implement Trie (Prefix Tree)
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55
55. Course Schedule II
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56
56. Add and Search Word - Data structure design
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57
57. Word Search II
Best soln, one submitted 6/4, best for time and ease to implement
58
58. House Robber II
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59
59. Contains Duplicate
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60
60. Invert Binary Tree
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61
61. Basic Calculator II
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62
62. Kth Smallest Element in a BST
Followup:
add self.numLeft = #values in left subtree + node itself
start at root.
if root.numLeft == k: return root
if root.numLeft > k: root = root.left
if root.numLeft < k: k - = root.numLeft; root = root.right
63
63. Lowest Common Ancestor of a Binary Search Tree
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64
64. Product of Array Except Self
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65
65. Sliding Window Maximum
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66
66. Search a 2D Matrix II
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67
67. Valid Anagram
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68
68. Meeting Rooms
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69
69. Meeting Rooms II
Also 2 ptr solution
70
70. Graph Valid Tree************
TODO: Union Find
71
71. Missing Number
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72
72. Alien Dictionary
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73
73. Encode and Decode Strings
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74
74. Integer to English Words********************************
MARKED AS 5 BC I DON'T WANT TO MEMORIZE IT RN
75
75. Find Median from Data Stream
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76
76. Serialize and Deserialize Binary Tree
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77
77. Longest Increasing Subsequence
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78
78. Coin Change
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79
79. Number of Connected Components in an Undirected Graph*******
TODO: Union Find
80
80. Counting Bits
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81
81. Top K Frequent Elements*************
TODO: QUICKSELECT!
1. Min heap: O(nlog(k))
2. Max heap: O(n + klog(n))
3. Quick Select: O(n) O(n^2) worst
4. Bucket Sort: O(n)
82
82. Sum of Two Integers
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83
83. Insert Delete GetRandom O(1)
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84
84. Pacific Atlantic Water Flow
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85
85. Longest Repeating Character Replacement
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86
86. Non-overlapping Intervals
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87
87. LFU Cache******************
TODO B/C Hard
88
88. Concatenated Words
OJ is fucked up, my TLE submitted 6/9 is correct
| Could do top-down version, seems easy
89
89. Encode and Decode TinyURL
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90
90. Subtree of Another Tree
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91
91. Design In-Memory File System
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92
92. Design Search Autocomplete System
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93
93. Palindromic Substrings
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94
94. Top K Frequent Words
1. sorting nlog(n)
3. minheap nlog(k) (complicated by python heap module)
4. bucket sort + trie O(n)
95
95. Number of Distinct Islands
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96
96. Flood Fill
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97
97. Partition Labels
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98
98. Most Common Word
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99
99. All Nodes Distance K in Binary Tree
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100
100. Snakes and Ladders
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101
101. Reorder Data in Log Files
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102
103. K Closest Points to Origin***************
TODO: Quickselect
103
104. Rotting Oranges
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104
105. Path With Maximum Minimum Value
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105
107. Minimum Cost to Connect Sticks
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106
108. Longest Common Subsequence
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107
109. Critical Connections in a Network
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108
110. Search Suggestions System
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