| idx | name | category | from | answer | note |
|---|---|---|---|---|---|
| 0 | Merging meeting times | array | Interview Cake | A | + |
| 1 | Reverse array in place | array | Interview Cake | A | + |
| 2 | Reverse words | array | Interview Cake | A | - |
| 3 | Merge sorted array | array | Interview Cake | A | - |
| 4 | Single riffle check | array | Interview Cake | A | + |
| 5 | Longest substring | string | LeetCode | A | - |
| 6 | Container with most water | array | LeetCode | A | - |
| 7 | Three sum | array | LeetCode | A | ! |
| 8 | Inflight entertainment | hash | Interview Cake | A | +! |
| 9 | Unique string | string | CTCI 1.1 | A | + |
| 10 | Check permutation | string | CTCI 1.2 | A | + |
| 11 | Urlify | string | CTCI 1.3 | A | - |
| 12 | Palindrome permutation | string | CTCI 1.4 | A | + |
| 13 | One away | string | CTCI 1.5 | A | + |
| 14 | String compression | string | CTCI 1.6 | A | + |
| 15 | Rotate matrix | array | CTCI 1.7 | A | + |
| 16 | Set matrix zeros | array | CTCI 1.8 | A | ! |
| 17 | String rotation | string | CTCI 1.9 | A | ! |
| 18 | Remove duplicates | linked list | LeetCode | A | ! |
| 19 | Remove nth from end | linked list | LeetCode | A | + |
| 20 | Delete node | linked list | LeetCode | A | + |
| 21 | Partition list | linked list | LeetCode | A | + |
| 22 | Add two numbers | linked list | LeetCode | A | + |
| 23 | Palindrome | linked list | LeetCode | A | ! |
| 24 | Intersection | linked list | LeetCode | A | ! |
| 25 | Loop detection | linked list | LeetCode | A | + |
| 26 | Next permutation | array | LeetCode | A | -! |
| 27 | Multiply Strings | string | LeetCode | A | + |
| 28 | Jump Game | array | LeetCode | A | - |
| 29 | Plus One | array | LeetCode | A | + |
| 30 | Minimum window substring | string | LeetCode | A | !! |
| 31 | Longest Valid Parentheses | string | LeetCode | A | - |
| 32 | Trapping rain water | array | LeetCode | A | -! |
| 33 | Valid parentheses | string | LeetCode | A | + |
| 34 | basic calculator | string | leetcode | A | - |
| 35 | decode string | string | leetcode | A | -! |
| 36 | min stack | array | leetcode | A | +! |
| 37 | queue using stacks | array | leetcode | A | + |
| 38 | odd even jumps | array | leetcode | A | ! |
| 39 | task scheduler | array | leetcode | A | ! |
| 40 | merge two sorted lists | linked list | leetcode | A | + |
| 41 | K closest points to origin | heap | leetcode | A | +! |
| 42 | Merge K sorted lists | heap | leetcode | A | +! |
| 43 | Kth largest element | heap | leetcode | A | +! |
| 44 | Find Median from Data Stream | heap | leetcode | A | -! |
| 45 | Two sum | hash | leetcode | A | ++! |
| 46 | Group Anagrams | hash | leetcode | A | -! |
| 47 | Subarray Sum Equals K | hash | leetcode | A | - |
| 48 | Palindrome Pairs | hash | leetcode | A | ! |
| 49 | Copy List with Random Pointer | hash | leetcode | A | +! |
| 50 | Insert Delete GetRandom O(1) | hash | leetcode | A | + |
| 51 | Backspace String Compare | string | leetcode | A | +- |
| 52 | Maximal Rectangle | array | leetcode | A | - |
| 53 | Read N char given read4 | array | leetcode | A | + |
| 54 | Longest Substring with At Most Two Distinct Characters | array | leetcode | A | + |
| 55 | Simplify Path | string | leetcode | A | + |
| 56 | Serialize and Deserialize Binary Tree | tree | leetcode | A | - |
| 57 | Binary Tree Maximum Path Sum | tree | leetcode | A | + |
| 58 | Binary Tree Zigzag Level Order Traversal | tree | leetcode | A | + |
| 59 | Validate Binary Search Tree | tree | leetcode | A | - |
| 60 | Serialize and Deserialize BST | tree | leetcode | A | - |
| 61 | Binary Tree Right Side View | tree | leetcode | A | + |
| 62 | Lowest Common Ancestor of a Binary Tree | tree | leetcode | A | - |
| 63 | Symmetric Tree | tree | leetcode | A | +! |
| 64 | Jewels and Stones | hash | leetcode | A | + |
| 65 | Find Duplicate File in System | hash | leetcode | A | + |
| 66 | Subdomain Visit Count | hash | leetcode | A | + |
| 67 | Sliding Window Maximum | heap | leetcode | A | +! |
| 68 | Clone Graph | graph | leetcode | A | + |
| 69 | Course Schedule | graph | leetcode | A | - |
| 70 | Course Schedule2 | graph | leetcode | A | - |
| 71 | Reconstruct Itinerary | graph | leetcode | A | - |
| 72 | Evaluate Division | graph | leetcode | A | - |
| 73 | Network Delay Time | graph | leetcode | A | - |
| 74 | Is Graph Bipartite | graph | leetcode | A | + |
| 75 | Binary Tree Level Order Traversal | tree | leetcode | A | + |
| 76 | Subsets | bit manipulation | leetcode | A | + |
| 77 | Single Number | bit manipulation | leetcode | A | + |
| 78 | Single Number2 | bit manipulation | leetcode | A | +? |
| 79 | Majority Element | bit manipulation | leetcode | A | - |
| 80 | Bitwise AND of Numbers Range | bit manipulation | leetcode | A | ++!- |
| 81 | Missing Number | bit manipulation | leetcode | A | +! |
| 82 | Sum of Two Integers | bit manipulation | leetcode | A | ! |
| 83 | UTF-8 Validation | bit manipulation | leetcode | A | ! |
| 84 | Minimum Height Trees | graph | leetcode | A | ! |
| 85 | Reverse Integer | math | leetcode | A | + |
| 86 | Palindrome Number | math | leetcode | A | + |
| 87 | Divide Two Integers | math | leetcode | A | ! |
| 88 | Happy Number | math | leetcode | A | +! |
| 89 | Count Primes | math | leetcode | A | +! |
| 90 | Perfect Squares | math | leetcode | A | - |
| 91 | Least Operators to Express Number | math | leetcode | A | ! |
| 92 | Power of Two | bit manipulation | leetcode | A | ! |
| 93 | Longest Palindromic Substring | dynamic programming | leetcode | A | ! |
| 94 | Maximum Subarray | dynamic programming | leetcode | A | +! |
| 95 | Minimum Path Sum | dynamic programming | leetcode | A | + |
| 96 | Climbing Stairs | dynamic programming | leetcode | A | + |
| 97 | Decode Ways | dynamic programming | leetcode | A | + |
| 98 | Best Time to Buy and Sell Stock | dynamic programming | leetcode | A | + |
| 99 | Word Break | dynamic programming | leetcode | A | -! |
| 100 | Coin Change | dynamic programming | leetcode | A | + |
| 101 | Cherry Pickup | dynamic programming | leetcode | A | ! |
| 102 | Ugly Number II | math | leetcode | A | ! |
| 103 | Regular Expression Matching | dynamic programming | leetcode | A | ? |
| 104 | Median of Two Sorted Arrays | binary search | leetcode | A | +! |
| 105 | Search in Rotated Sorted Array | binary search | leetcode | A | ! |
| 106 | Merge Intervals | sort | leetcode | A | + |
| 107 | Time Based Key-Value Store | binary search | leetcode | A | !! |
| 108 | Split Array Largest Sum | binary search | leetcode | A | ! |
| 109 | Reorder Data in Log Files | string | leetcode | A | + |
| 110 | Product of Array Except Self | array | leetcode | A | ! |
| 111 | Game of Life | array | leetcode | A | ! |
| 112 | Generate Parentheses | array | leetcode | A | + |
| 113 | Letter Combinations of a Phone Number | string | leetcode | A | + |
| 114 | First Missing Positive | array | leetcode | A | +- |
| 115 | Move Zeroes | array | leetcode | A | ++- |
| 116 | Word Search | array | leetcode | A | - |
| 117 | Spiral Matrix | array | leetcode | A | + |
| 118 | 4Sum | hash | leetcode | A | - |
| 119 | Top K Frequent Elements | hash | leetcode | A | +! |
| 120 | Verifying an Alien Dictionary | hash | leetcode | A | + |
| 121 | Longest String Chain | hash | leetcode | A | + |
| 122 | Sudoku Solver | hash | leetcode | A | + |
| 123 | Swap Nodes in Pairs | linked list | leetcode | A | + |
| 124 | Reverse Linked List | linked list | leetcode | A | + |
| 125 | Add two numbers 2 | linked list | leetcode | A | -- |
| 126 | Reverse Nodes in k-Group | linked list | leetcode | A | - |
| 127 | Sort List | linked list | leetcode | A | ! |
| 128 | BST Iterator | tree (stack) | leetcode | A | - |
| 129 | House Robber | dp | leetcode | A | + |
| 130 | Maximal Square | dp | leetcode | A | - |
| 131 | Palindromic Substring | dp | leetcode | A | + |
| 132 | Combination Sum | dp | leetcode | A | -! |
| 133 | Maximum product subarray | dp | leetcode | A | -! |
| 134 | Longest increasing subsquence | dp | leetcode | A | + |
| 135 | Restore IP Addresses | dp | leetcode | A | + |
| 136 | Minimum Cost Tree From Leaf Values | dp | leetcode | A | -! |
| 137 | N-Queens | dp | leetcode | A | + |
| 138 | Unique BST | tree | leetcode | A | ! |
| 139 | Construct Binary Tree from Preorder and Inorder Traversal | tree | leetcode | A | ! |
| 140 | Count Complete Tree Nodes | tree | leetcode | A | +! |
| 141 | Subtree of Another Tree | tree | leetcode | A | +! |
| 142 | All Nodes Distance K in Binary Tree | tree | leetcode | A | ! |
| 143 | Diameter of Binary Tree | tree | leetcode | A | + |
| 144 | Recover Binary Search Tree | tree | leetcode | A | -! |
| 145 | Keys and Rooms | graph | leetcode | A | + |
| 146 | Find the town judge | graph | leetcode | A | ++ |
| 147 | Redundant Connection | graph | leetcode | A | -! |
| 148 | Regions Cut By Slashes | graph | leetcode | A | -! |
| 149 | Couples Holding Hands | graph | leetcode | A | -! |
| 150 | Similar String Groups | graph | leetcode | A | -! |
+: Solved within 30 min
-: Solved over 30 min
!: Got help from the solution
?: Still don't understand the solution (should try again)