| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 27 | Remove Element | O(n) | O(1) | Two Pointer |
| Leetcode 26 | Remove Duplicates from Sorted Array | O(n) | O(1) | Two Pointer |
| Leetcode 80 | Remove Duplicates from Sorted Array II | O(n) | O(1) | Two Pointer |
| Leetcode 277 | Find the Celebrity | O(n) | O(1) | |
| Leetcode 189 | Rotate Array | O(n) | O(1) | |
| Leetcode 41 | First Missing Positive | O(n | O(1) | Bucket Sort |
| Leetcode 299 | Bulls and Cows | O(n) | O(n) | |
| Leetcode 134 | Gas Station | O(n) | O(1) | |
| Leetcode 274 | H-Index | O(n) | O(n) | |
| Leetcode 275 | H-Index II | O(logn) | O(1) | Binary Search |
| Leetcode 244 | Shortest Word Distance II | O(n^2) | O(n) | Hashmap |
| Leetcode 245 | Shortest Word Distance III | O(n^2) | O(n) | |
| Leetcode 217 | Contains Duplicate | O(n) | O(n) | |
| Leetcode 219 | Contains Duplicate II | O(n) | O(n) | |
| Leetcode 220 | Contains Duplicate III | O(n^2 | O(1) | |
| Leetcode 55 | Jump Game | O(n) | O(1) | Greedy |
| Leetcode 45 | Jump Game II | O(n) | O(1) | Greedy |
| Leetcode 403 | Frog Jump | O(n) | O(n) | DFS |
| Leetcode 121 | Best Time to Buy and Sell Stock | O(n) | O(1) | |
| Leetcode 122 | Best Time to Buy and Sell Stock II | O(n) | O(1) | |
| Leetcode 123 | Best Time to Buy and Sell Stock III | O(n) | O(n) | |
| Leetcode 188 | Best Time to Buy and Sell Stock IV | O(n*k) | O(n*k) | DP |
| Leetcode 309 | Best Time to Buy and Sell Stock with Cooldown | O(n) | O(n) | DP |
| Leetcode 11 | Container With Most Water | O(n) | O(1) | Two Pointer |
| Leetcode 42 | Trapping Rain Water | O(n) | O(1) | Two Pointer |
| Leetcode 334 | Increasing Triplet Subsequence | O(n) | O(1) | |
| Leetcode 128 | Longest Consecutive Sequence | O(n) | O(n) | |
| Leetcode 287 | Find the Duplicate Number | O(nlogn) | O(1) | Binary Search |
| Leetcode 289 | Game of Life | O(m*n) | O(1) | |
| Leetcode 57 | Insert Interval | O(n) | O(1) | |
| Leetcode 56 | Merge Intervals | O(nlogn) | O(1) | |
| Leetcode 986 | Interval List Intersections | O(m+n) | O(1) | |
| Leetcode 252 | Meeting Rooms | O(nlogn) | O(1) | |
| Leetcode 253 | Meeting Rooms II | O(nlogn) | O(n) | |
| Leetcode 352 | Data Stream as Disjoint Intervals | O(n) | O(1) | |
| Leetcode 239 | Sliding Window Maximum | O(n) | O(n) | |
| Leetcode 295 | Find Median from Data Stream | O(nlogn) | O(n) | |
| Leetcode 1093 | Statistics from a Large Sample | O(1) | O(1) | 295 follow up |
| Leetcode 53 | Maximum Subarray | O(n) | O(n) | |
| Leetcode 325 | Maximum Size Subarray Sum Equals k | O(n) | O(n) | |
| Leetcode 209 | Minimum Size Subarray Sum | O(n) | O(1) | Two Pointer |
| Leetcode 238 | Product of Array Except Self | O(n) | O(n) | |
| Leetcode 152 | Maximum Product Subarray | O(n) | O(1) | |
| Leetcode 228 | Summary Ranges | O(n) | O(1) | |
| Leetcode 163 | Missing Ranges | O(n) | O(1) | |
| Leetcode 88 | Merge Sorted Array | O(n) | O(1) | Two Pointer |
| Leetcode 75 | Sort Colors | O(n) | O(1) | Two Pointer |
| Leetcode 283 | Move Zeroes | O(n) | O(1) | Two Pointer |
| Leetcode 376 | Wiggle Subsequence | O(n) | O(1) | |
| Leetcode 280 | Wiggle Sort | O(n) | O(1) | |
| Leetcode 324 | Wiggle Sort II | O(n) | O(n) | |
| Leetcode 560 | Subarray Sum Equals K | O(n) | O(n) | |
| Leetcode 4 | Median of Two Sorted Arrays | py | O(m+n) | |
| Leetcode 1239 | Maximum Length of a Concatenated String with Unique Characters | O(2^n) | O(n) | |
| Leetcode 135 | Candy | O(n) | O(n) | |
| Leetcode 581 | Shortest Unsorted Continuous Subarray | O(n) | O(n) | |
| Leetcode 503 | Next Greater Element II | O(n) | O(n) | |
| Leetcode 496 | Next Greater Element I | O(n) | O(n) | |
| Leetcode 525 | Contiguous Array | O(n) | O(n) | |
| Leetcode 977 | Squares of a Sorted Array | O(n) | O(n) |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 28 | Implement strStr() | O((n-l)*l) | O(1) | |
| Leetcode 186 | Reverse Words in a String II | O(n) | O(1) | |
| Leetcode 205 | Isomorphic Strings | O(n) | O(n) | HashMap |
| Leetcode 293 | Flip Game | O(n) | O(1) | |
| Leetcode 294 | Flip Game II | O(n!) | O(n!) | BackTracking |
| Leetcode 290 | Word Pattern | O(n) | O(n) | HashMap |
| Leetcode 242 | Valid Anagram | O(nlogn) | O(1) | |
| Leetcode 49 | Group Anagrams | O(n) | O(n) | |
| Leetcode 249 | Group Shifted Strings | O(n) | O(n) | |
| Leetcode 161 | One Edit Distance | O(n) | O(1) | |
| Leetcode 38 | Count and Say | O(2^n) | O(1) | |
| Leetcode 316 | Remove Duplicate Letters | O(n) | O(1) | |
| Leetcode 271 | Encode and Decode Strings | O(n) | O(1) | |
| Leetcode 168 | Excel Sheet Column Title | O(n) | O(1) | |
| Leetcode 171 | Excel Sheet Column Number | O(n) | O(1) | |
| Leetcode 13 | Roman to Integer | O(1) | O(1) | |
| Leetcode 12 | Integer to Roman | O(n) | O(1) | |
| Leetcode 273 | Integer to English Words | O(n) | O(1) | |
| Leetcode 157 | Read N Characters Given Read4 | O(n) | O(1) | |
| Leetcode 158 | Read N Characters Given Read4 II - Call multiple times | O(n) | O(n) | |
| Leetcode 68 | Text Justification | O(n) | O(n/kπ) | |
| Leetcode 76 | Minimum Window Substring | O(n) | O(n) | Sliding Window |
| Leetcode 3 | Longest Substring Without Repeating Characters | O(n) | O(m) | Sliding Window |
| Leetcode 340 | Longest Substring with At Most K Distinct Characters | O(n) | O(k) | Sliding Window |
| Leetcode 125 | Valid Palindrome | O(n) | O(1) | Two Pointer |
| Leetcode 680 | Valid Palindrome II | O(n) | O(n) | Two Pointer |
| Leetcode 5 | Longest Palindromic Substring | O(n^2) | O(n^2) | DP |
| Leetcode 516 | Longest Palindromic Subsequence | O(n^2) | O(n^2) | DP |
| Leetcode 214 | Shortest Palindrome | O(n) | O(n) | |
| Leetcode 336 | Palindrome Pairs | O(nk^2) | O(n) | |
| Leetcode 1246 | Palindrome Removal | O(n^3) | O(n^2) | |
| Leetcode 20 | Valid Parentheses | O(n) | O(n) | |
| Leetcode 1249 | Minimum Remove to Make Valid Parentheses | O(n) | O(n) | |
| Leetcode 22 | Generate Parentheses | O(4^n)? | O(n)? | BackTracking |
| Leetcode 32 | Longest Valid Parentheses | O(n) | O(n) | DP |
| Leetcode 241 | Different Ways to Add Parentheses | ? | ? | Divide&Conquer |
| Leetcode 301 | Remove Invalid Parentheses | O(n*2^n) | O(2^n) | BFS |
| Leetcode 678 | Valid Parenthesis String | O(3^n) | O(n) | BFS |
| Leetcode 115 | Distinct Subsequences | O(mn) | O(mn) | BackTracking |
| Leetcode 844 | Backspace String Compare | O(m+n) | O(1) | Two Pointer |
| Leetcode 763 | Partition Labels | O(n) | O(n) | |
| Leetcode 616 | Add Bold Tag in String | ? | O(n) | |
| Leetcode 97 | Interleaving String | O(mn) | O(mn) | |
| Leetcode 767 | Reorganize String | O(nlogn) | O(n) | |
| Leetcode 438 | Find All Anagrams in a String | O(n) | O(n) | |
| Leetcode 1156 | Swap For Longest Repeated Character Substring | O(n) | O(n) |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 7 | Reverse Integer | O(n) | O(1) | |
| Leetcode 66 | Plus One | O(n) | O(1) | |
| Leetcode 8 | String to Integer (atoi) | O(n) | O(1) | |
| Leetcode 67 | Add Binary | O(n) | O(1) | |
| Leetcode 445 | Add Two Numbers II | O(n) | O(n) | |
| Leetcode 43 | Multiply Strings | O(m*n) | O(m+n) | |
| Leetcode 29 | Divide Two Integers | O(n) | O(1) | |
| Leetcode 69 | Sqrt(x) | O(logn) | O(1) | Binary Search |
| Leetcode 50 | Pow(x, n) | O(logn) | O(1) or O(logn) | |
| Leetcode 367 | Valid Perfect Square | O(logn) | O(1) | Binary Search |
| Leetcode 204 | Count Primes | O(nloglogn) | O(n) | |
| Leetcode 1 | Two Sum | O(n) | O(n) | |
| Leetcode 15 | 3Sum | O(n^2) | O(logn)~O(n) | |
| Leetcode 18 | 4Sum | O(n^3) | O(logn)~O(n) | |
| Leetcode 231 | Power of Two | O(logn) | O(1) | |
| Leetcode 202 | Happy Number | O(logn) | O(logn) | |
| Leetcode 263 | Ugly Number | O(logn) | O(1) | |
| Leetcode 264 | Ugly Number II | O(n) | O(n) | |
| Leetcode 223 | Rectangle Area | O(1) | O(1) | |
| Leetcode 670 | Maximum Swap | O(n) | O(n) |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 100 | Same Tree | O(n) | O(logn)~O(n) | |
| Leetcode 101 | Symmetric Tree | O(n) | O(n) | |
| Leetcode 226 | Invert Binary Tree | O(n) | O(n) | |
| Leetcode 257 | Binary Tree Paths | O(n) | O(n) | |
| Leetcode 112 | Path Sum | O(n) | O(n) | |
| Leetcode 113 | Path Sum II | O(n) | O(n) | |
| Leetcode 298 | Binary Tree Longest Consecutive Sequence | O(n) | O(n) | |
| Leetcode 111 | Minimum Depth of Binary Tree | O(n^2) | O(n) | |
| Leetcode 104 | Maximum Depth of Binary Tree | O(n) | O(n) | |
| Leetcode 110 | Balanced Binary Tree | O(nlogn) | O(n) | |
| Leetcode 124 | Binary Tree Maximum Path Sum | O(n) | O(logn) | 543 |
| Leetcode 337 | House Robber III | O(n) | O(n) | |
| Leetcode 98 | Validate Binary Search Tree | O(n) | O(n) | |
| Leetcode 235 | Lowest Common Ancestor of a Binary Search Tree | O(n) | O(n) | BST |
| Leetcode 236 | Lowest Common Ancestor of a Binary Tree | O(n) | O(n) | |
| Leetcode 108 | Convert Sorted Array to Binary Search Tree | O(n) | O(n) | BST |
| Leetcode 173 | Binary Search Tree Iterator | O(n) | O(n) | BST |
| Leetcode 230 | Kth Smallest Element in a BST | O(n) | O(n) | BST |
| Leetcode 297 | Serialize and Deserialize Binary Tree | O(n) | O(n) | |
| Leetcode 285 | Inorder Successor in BST | O(n) | O(H) | BST |
| Leetcode 270 | Closest Binary Search Tree Value | O(n) | O(H) | BST |
| Leetcode 116 | Populating Ne\xt Right Pointers in Each Node | O(n) | O(logn) | |
| Leetcode 117 | Populating Next Right Pointers in Each Node II | O(n) | O(n) | |
| Leetcode 314 | Binary Tree Vertical Order Traversal | O(nlogn) | O(n) | |
| Leetcode 96 | Unique Binary Search Trees | O(n^2) | O(n) | DP |
| Leetcode 105 | Construct Binary Tree from Preorder and Inorder Traversal | O(n) | O(n) | |
| Leetcode 106 | Construct Binary Tree from Inorder and Postorder Traversal | O(n) | O(n) | |
| Leetcode 889 | Construct Binary Tree from Preorder and Postorder Traversal | O(n^2) | O(n) | |
| Leetcode 1008 | Construct Binary Search Tree from Preorder Traversal | O(n) | O(n) | |
| Leetcode 199 | Binary Tree Right Side View | O(n) | O(n) | |
| Leetcode 545 | Boundary of Binary Tree | O(n) | O(n) | |
| Leetcode 366 | Find Leaves of Binary Tree | O(n) | O(n) | |
| Leetcode 863 | All Nodes Distance K in Binary Tree | O(n) | O(n) | |
| Leetcode 109 | Convert Sorted List to Binary Search Tree | O(nlogn) | O(nlogn) | |
| Leetcode 103 | Binary Tree Zigzag Level Order Traversal | O(n) | O(n) | |
| Leetcode 543 | Diameter of Binary Tree | O(n) | O(logn) | 124 |
| Leetcode 428 | Serialize and Deserialize N-ary Tree | O(n) | O(n) | |
| Leetcode 987 | Vertical Order Traversal of a Binary Tree | O(n) | O(n) | |
| Leetcode 938 | Range Sum of BST | O(n) | O(1) | |
| Leetcode 450 | Delete Node in a BST | O(logn) | O(logn) | |
| Leetcode 549 | Binary Tree Longest Consecutive Sequence II | __ | __ | |
| Leetcode 1339 | Maximum Product of Splitted Binary Tree | O(n) | O(n) |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 200 | Number of Islands | O(mn) | O(min(m,n))~O(mn) | BFS/DFS/Recursive |
| Leetcode 286 | Walls and Gates | O(mn) | O(mn) | BFS/DFS |
| Leetcode 130 | Surrounded Regions | O(mn) | O(mn) | DFS |
| Leetcode 339 | Nested List Weight Sum | O(n) | O(n) | BFS |
| Leetcode 364 | Nested List Weight Sum II | O(n) | O(n) | BFS |
| Leetcode 127 | Word Ladder | O(n*26^len) | O(n) | BFS |
| Leetcode 126 | Word Ladder II | O(n*26^len) | O(n+p*l) | BFS |
| Leetcode 695 | Max Area of Island | O(mn) | O(mn) | BFS |
| Leetcode 490 | The Maze | O(mn) | O(mn) | BFS |
| Leetcode 505 | The Maze II | O(mn*log(mn)) | O(mn) | Heap |
| Leetcode 675 | Cut Off Trees for Golf Event | O(mn*log(mn)) | O(mn) | |
| Leetcode 1436 | Destination City | __ | __ | |
| Leetcode 332 | Reconstruct Itinerary | __ | __ | |
| Leetcode 787 | Cheapest Flights Within K Stops | py | O(n) | Dijkstra |
| Leetcode 743 | Network Delay Time | __ | __ | Dijkstra |
| Leetcode 994 | Rotting Oranges | O(mn) | O(mn) | BFS |
| Leetcode 815 | Bus Routes | __ | __ | BFS |
| Leetcode 638 | Shopping Offers | __ | __ | |
| Leetcode 1269 | Number of Ways to Stay in the Same Place After Some Steps | __ | __ | |
| Leetcode 329 | Longest Increasing Path in a Matrix | __ | __ | |
| Leetcode 1197 | Minimum Knight Moves | __ | __ | BFS |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 78 | Subsets | O(n*2^n) | O(n) | |
| Leetcode 90 | Subsets II | O(n*2^n) | O(n) | |
| Leetcode 77 | Combinations | O(k*Cnk) | O(k)? | |
| Leetcode 39 | Combination Sum | ？ | O(n)? | |
| Leetcode 40 | Combination Sum II | ？ | O(n)? | |
| Leetcode 216 | Combination Sum III | ? | O(n)? | |
| Leetcode 254 | Factor Combinations | O(2^n)? | O(n)? | |
| Leetcode 46 | Permutations | O(n!) | O(n) | |
| Leetcode 47 | Permutations II | O(n!)? | ? | |
| Leetcode 31 | Next Permutation | O(n) | O(1) | |
| Leetcode 60 | Permutation Sequence | O(n!) | O(n) | |
| Leetcode 291 | Word Pattern II | O(n*(Cnm) | On) | |
| Leetcode 17 | Letter Combinations of a Phone Number | O(3^n*4^m | O(n) | |
| Leetcode 282 | Expression Add Operators | O(n*4^n) | O(n) | |
| Leetcode 140 | Word Break II | O(n^2) | O(n) | |
| Leetcode 351 | Android Unlock Patterns | O(n!) | O(n) | |
| Leetcode 51 | N-Queens | O(n!) | O(n) | |
| Leetcode 52 | N-Queens II | O(n!) | O(n) | |
| Leetcode 491 | Increasing Subsequences | O(2^n) | O(2^n) | |
| Leetcode 1192 | Critical Connections in a Network | O(V+E) | O(n) | |
| Leetcode 93 | Restore IP Addresses | O(2^n) | O(2^n) |
Backtracking 的时间复杂度
# 在backtracking函数中，for 循环里有几种选择就是几的n次方, 最少的2^n 例如 下面这种情况是O(3^n)
def bt(self,idx,n):
for i in range(idx, n):
self.bt()
self.bt()
self.bt()
# 在bt函数中，如果每次for循环都是T-1，那么时间复杂度 是 O(2^n)
def bt(self,idx,n):
for i in range(idx, n):
self.bt(i+1, n)
# 在bt函数中，如果每次for循环都是重新遍历(不重复上一步），那么时间复杂度 是 O(n！)
def bt(self,idx,n, visited):
for i in range(n):
if i not in visited:
visited.add(i)
self.bt(i+1, n, visited)
visited.remove(i)| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 70 | Climbing Stairs | O(n) | O(n) | |
| Leetcode 62 | Unique Paths | O(n*m) | O(n*m) | Same as 64 |
| Leetcode 64 | Minimum Path Sum | O(m*n) | O(m*n) | |
| Leetcode 279 | Perfect Squares | O(n*n^0.5) | O(n) | Same as 322,377 |
| Leetcode 322 | Coin Change | O(s*n) | O(s) | |
| Leetcode 377 | Combination Sum IV | O(s*n) | O(s) | |
| Leetcode 139 | Word Break | O(n^2) | O(n) | |
| Leetcode 375 | Guess Number Higher or Lower II | O(n^3) | O(n^2) | |
| Leetcode 256 | Paint House | O(n) | O(n) | |
| Leetcode 265 | Paint House II | O(nk^2) | O(nk) | |
| Leetcode 72 | Edit Distance | O(mn) | O(mn) | |
| Leetcode 174 | Dungeon Game | O(mn) | O(mn) | |
| Leetcode 221 | Maximal Square | O(mn) | O(mn) | |
| Leetcode 85 | Maximal Rectangle | O(mn) | O(mn) | |
| Leetcode 312 | Burst Balloons | O(n^3) | O(n^2) | |
| Leetcode 198 | House Robber | O(n) | O(n) | |
| Leetcode 213 | House Robber II | O(n) | O(n) | |
| Leetcode 276 | Paint Fence | O(n) | O(n) | |
| Leetcode 91 | Decode Ways | O(n) | O(n) | |
| Leetcode 10 | Regular Expression Matching | O(mn) | O(mn) | |
| Leetcode 44 | Wildcard Matching | O(mn) | O(mn) | |
| Leetcode 1143 | Longest Common Subsequence | O(mn) | O(mn) | |
| Leetcode 472 | Concatenated Words | O(nl) | O(l) | |
| Leetcode 983 | Minimum Cost For Tickets | O(n) | O(n) | |
| Leetcode 368 | Largest Divisible Subset | O(n^2) | O(n^2) |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 278 | First Bad Version | __ | __ | |
| Leetcode 35 | Search Insert Position | __ | __ | |
| Leetcode 33 | Search in Rotated Sorted Array | __ | __ | |
| Leetcode 81 | Search in Rotated Sorted Array II | __ | __ | |
| Leetcode 153 | Find Minimum in Rotated Sorted Array | __ | __ | |
| Leetcode 154 | Find Minimum in Rotated Sorted Array II | __ | __ | |
| Leetcode 162 | Find Peak Element | __ | __ | |
| Leetcode 374 | Guess Number Higher or Lower | __ | __ | |
| Leetcode 34 | Find First and Last Position of Element in Sorted Array | __ | __ | |
| Leetcode 350 | Intersection of Two Arrays II | __ | __ | Two Pointer/HashMap/BS |
| Leetcode 300 | Longest Increasing Subsequence | O(nlogn)/O(n^2) | O(n) | BS/DP |
| Leetcode 354 | Russian Doll Envelopes | O(nlogn)/O(n^2) | O(n) | BS/DP |
| Leetcode 658 | Find K Closest Elements | __ | __ |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 155 | Min Stack | O(1) | O(n) | |
| Leetcode 232 | Implement Queue using Stacks | O(1) | O(n) | 2 stacks |
| Leetcode 225 | Implement Stack using Queues | O(1)~O(n) | O(n) | 2 queues |
| Leetcode 150 | Evaluate Reverse Polish Notation | O(n) | O(n) | |
| Leetcode 71 | Simplify Path | O(n) | O(n) | |
| Leetcode 394 | Decode String | O(n) | O(n) | 2 stacks |
| Leetcode 224 | Basic Calculator | O(n) | O(n) | 2 stacks |
| Leetcode 227 | Basic Calculator II | O(n) | O(n) | |
| Leetcode 385 | Mini Parser | O(n) | _O(n)klkj _ | |
| Leetcode 84 | Largest Rectangle in Histogram | O(n) | O(n) | |
| Leetcode 215 | Kth Largest Element in an Array | O(nlogn) | O(n) | |
| Leetcode 347 | Top K Frequent Elements | O(n) | O(n) | bucket sort |
| Leetcode 692 | Top K Frequent Words | O(nlogn) | O(n) | bucket sort |
| Leetcode 218 | The Skyline Problem | O(nlogn) | O(n) | |
| Leetcode 341 | Flatten Nested List Iterator | O(n) | O(N) | |
| Leetcode 373 | Find K Pairs with Smallest Sums | O(klogk) | O(k) | |
| Leetcode 378 | Kth Smallest Element in a Sorted Matrix | O(klogk) | O(k) | |
| Leetcode 1439 | Find K Pairs with Smallest Sums of Matrix | __ | __ | |
| Leetcode 739 | Daily Temperatures | O(n) | O(n) | |
| Leetcode 621 | Task Scheduler | __ | __ |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 48 | Rotate Image | __ | __ | |
| Leetcode 54 | Spiral Matrix | __ | __ | |
| Leetcode 59 | Spiral Matrix II | __ | __ | |
| Leetcode 1439 | Find the Kth Smallest Sum of a Matrix With Sorted Rows | __ | __ | Divide&Conquer |
| Leetcode 1311 | Sparse Matrix Multiplication | __ | __ | |
| Leetcode 1378 | Kth Smallest Element in a Sorted Matrix | __ | __ | |
| Leetcode 174 | Search a 2D Matrix | __ | __ | |
| Leetcode 1240 | Search a 2D Matrix II | O(m+n) | O(1) | |
| Leetcode 179 | Word Search | __ | __ | |
| Leetcode 1219 | Path with Maximum Gold | __ | __ | Same as word search |
| Leetcode 1361 | Bomb Enemy | __ | __ | |
| Leetcode 136 | Valid Sudoku | __ | __ | |
| Leetcode 137 | Sudoku Solver | __ | __ | BackTracking |
| Leetcode 909 | Snakes and Ladders | __ | __ | BFS |
| Leetcode 1102 | Path With Maximum Minimum Value | __ | __ | Greedy |
| Leetcode 296 | Best Meeting Point | __ | __ | BFS |
| Leetcode 317 | Shortest Distance from All Buildings | __ | __ | BFS |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 206 | Reverse Linked List | __ | __ | |
| Leetcode 141 | Linked List Cycle | __ | __ | |
| Leetcode 24 | Swap Nodes in Pairs | __ | __ | |
| Leetcode 328 | Odd Even Linked List | __ | __ | |
| Leetcode 92 | Reverse Linked List II | __ | __ | |
| Leetcode 237 | Delete Node in a Linked List | __ | __ | |
| Leetcode 19 | Remove Nth Node From End of List | __ | __ | |
| Leetcode 83 | Remove Duplicates from Sorted List | __ | __ | |
| Leetcode 203 | Remove Linked List Elements | __ | __ | |
| Leetcode 82 | Remove Duplicates from Sorted List II | __ | __ | |
| Leetcode 369 | Plus One Linked List | __ | __ | |
| Leetcode 2 | Add Two Numbers | __ | __ | |
| Leetcode 160 | Intersection of Two Linked Lists | __ | __ | |
| Leetcode 21 | Merge Two Sorted Lists | __ | __ | |
| Leetcode 234 | Palindrome Linked List | __ | __ | |
| Leetcode 143 | Reorder List | __ | __ | |
| Leetcode 142 | Linked List Cycle II | __ | __ | |
| Leetcode 148 | Sort List | __ | __ | Merge sort(Divide&Conquer) |
| Leetcode 25 | Reverse Nodes in k-Group | __ | __ | Recursive |
| Leetcode 61 | Rotate List | __ | __ | |
| Leetcode 86 | Partition List | __ | __ | Two Pointer |
| Leetcode 23 | Merge k Sorted Lists | __ | __ | Merge sort |
| Leetcode 147 | Insertion Sort List | __ | __ | Insertion sort |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 207 | Course Schedule | __ | __ | |
| Leetcode 210 | Course Schedule II | __ | __ | |
| Leetcode 269 | Alien Dictionary | __ | __ |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 136 | Single Number | __ | __ | |
| Leetcode 318 | Maximum Product of Word Lengths | __ | __ |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 384 | Shuffle an Array | __ | __ | |
| Leetcode 398 | Random Pick Index | __ | __ | |
| Leetcode 382 | Linked List Random Node | __ | __ | |
| Leetcode 380 | Insert Delete GetRandom O(1) | __ | __ | |
| Leetcode 381 | Insert Delete GetRandom O(1) - Duplicates allowed | __ | __ |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 133 | Clone Graph | __ | __ | |
| Leetcode 138 | Copy List with Random Pointer | O(n) | O(n) | |
| Leetcode 399 | Evaluate Division | __ | __ | DFS |
| Leetcode 310 | Minimum Height Trees | __ | __ | Topological Sort |
| Leetcode 1152. Analyze User Website Visit Pattern | __ | __ | Topological Sort |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 261 | Graph Valid Tree | __ | __ | UF/DFS |
| Leetcode 323 | Number of Connected Components in an Undirected Graph | __ | __ | UF/DFS |
| Leetcode 305 | Number of Islands II | __ | __ |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 208 | Implement Trie (Prefix Tree) | __ | __ | |
| Leetcode 211 | Add and Search Word - Data structure design | __ | __ | DFS with Trie |
| Leetcode 212 | Word Search II | __ | __ | BackTrakcing with Trie |
| Leetcode 642 | Design Search Autocomplete System | __ | __ | |
| Leetcode 588 | Design In-Memory File System | __ | __ | |
| Leetcode 635 | Design Log Storage System | __ | __ |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| Leetcode 359 | Logger Rate Limiter | __ | __ | Buffer |
| Leetcode 362 | Design Hit Counter | __ | __ | Buffer |
| Leetcode 346 | Moving Average from Data Stream | __ | __ | |
| Leetcode 281 | Zigzag Iterator | __ | __ | |
| Leetcode 284 | Peeking Iterator | __ | __ | |
| Leetcode 251 | Flatten 2D Vector | __ | __ | |
| Leetcode 146 | LRU Cache | __ | __ | Doubly liked list |
| Leetcode 460 | LFU Cache | O(1) | O(n) | Doubly liked list |
| Leetcode 303 | Range Sum Query - Immutable | __ | __ | PreSum |
| Leetcode 170 | Two Sum III - Data structure design | __ | __ | |
| Leetcode 348 | Design Tic-Tac-Toe | __ | __ | |
| Leetcode 353 | Design Snake Game | __ | __ | |
| Leetcode 355 | Design Twitter | __ | __ | OOD |
| Leetcode 706 | Design HashMap | __ | __ | |
| Leetcode 622 | Design Circular Queue | __ | __ | |
| Leetcode 895 | Maximum Frequency Stack | __ | __ | |
| Leetcode 307 | Range Sum Query - Mutable | O(logn)~O(n) | O(n) | Segment Trees |
| # | Title | Time | Space | Remark |
|---|---|---|---|---|
| First Unique Number | __ | __ | Doubly liked list | |
| Integer to Chinese | __ | __ | ||
| Print Nodes in Top View of Binary Tree | __ | __ | ||
| Bottom View of Binary Tree | __ | __ | ||
| K Decimal Addition | __ | __ |