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