Leetcode Solutions Swift
Leetcode solutions in Swift
Current Finished: 131
String(19)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 3 Longest Substring without repeating characters | String | Medium | O(n) | O(n) |
| 14 Longest Common Prefix | String | Easy | O(nm) | O(mn) |
| 28 Implement strStr | String | Easy | O(n) | O(mn) |
| 49 Group Anagrams | String | Medium | O(Nmlgm) | O(N) |
| 58 Length of Last Word | String | Easy | O(n) | O(n) |
| 165 Compare Version Numbers | String | Easy | O(n) | O(n) |
| 205 Isomorphic Strings | String | Easy | O(n) | O(n) |
| 242 Valid Anagram | String | Easy | O(n) | O(n) |
| 293 Flip Game |
String | Easy | O(N) | O(N) |
| 294 Flip Game |
String | Medium | O(2^(n/2)) | O(2^(n/2)) |
| 290 Word Pattern | String | Easy | O(n) | O(n) |
| 340 Longest SubString with At Most K Distinct Characters |
String | Hard | O(1) | O(N) |
| 344 Reverse String | String | Easy | O(n) | O(n) |
| 345 Reverse Vowels of a String | String | Easy | O(n) | O(n) |
| 383 Ransom Note | String | Easy | O(n) | O(n) |
| 388 Longest Absolute File Path Solution | String | Medium | O(N) | O(N) |
| 389 Find the difference | String & hash table | Easy | O(n) | O(n) |
| 394 Decode String | String | Medium | O(N) | O(N) |
| 418 Sentence Screen Fitting |
String | Medium | O(1) | O(row * col) |
Array(22)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 1 Two Sum | Array | Easy | O(n) | O(n) |
| 15 3Sum | Array | Medium | O(n) | O(n^2) |
| 18 4Sum | Array | Medium | O(N^2) | O(N^4) |
| 26 Remove Duplicates from sorted array | Array | Easy | O(N) | O(N) |
| 27 Remove Element | Array | Easy | O(1) | O(n) |
| 36 Valid Sudoku | Array | Easy | O(1) | O(1) |
| 48 Rotate Image | Array | Medium | O(1) | O(n^2) |
| 80 Remove Duplicates from sorted array II | Array | Medium | O(N) | O(N) |
| 189 Rotate Array | Array | Easy | O(1) | O(n) |
| 217 Contains Duplicate | Array | Easy | O(n) | O(n) |
| 228 Summary Ranges | Array | Medium | O(n) | O(n) |
| 260 Single Number III | Array/Bit | Medium | O(1) | O(n) |
| 283 Move Zeroes | Array | Easy | O(1) | O(n) |
| 303 Range Sum Query - Immutable | Array | Easy | O(N) | O(N) |
| 304 Range Sum Query 2D - Immutable | Array | Medium | O(N^2) | O(N^2) |
| 308 Range Sum Query 2D - Mutable | Array | Hard | O(N^2) | O(N^2) |
| 349 Intersection of two arrays | Array | Easy | O(n) | O(n) |
| 350 Intersection of two arrays II | Array | Easy | O(n) | O(n) |
| 361 Bomb Enemy |
Array | Medium | O(N) | O(MN) |
| 457 Circular Array Loop | Array | Medium | O(1) | O(N) |
| 621 Task Scheduler | Array | Medium | O(1) | O(N) |
| 645 Set Mismatch | Array | Medium | O(N) | O(N) |
Tree(20)
Graph(1)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 207 Course Schedule | Graph | Medium | O( | V |
Search(9)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 33 Search in rotated sorted array | Search | Hard | O(1) | O(lgn) |
| 34 Search for a Range | Search | Medium | O(1) | O(lgn) |
| 35 Search Insert Position | Search | Medium | O(1) | O(lgn) |
| 69 Sqrtx | Search | Medium | O(1) | O(lgn) |
| 81 Search in rotated sorted array II | Search | Medium | O(1) | O(n) |
| 153 Find Minimum in Rotated Sorted Array | Search | Medium | O(1) | O(lgn) |
| 154 Find Minimum in Rotated Sorted Array II | Search | Medium | O(1) | O(n) |
| 162 Find Peak Element | Search | Medium | O(1) | O(lgn) |
| 278 First Bad Version | Binary Search | Easy | O(1) | O(lgn) |
Linked List(8)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 2 Add Two Numbers | LinkedList | Medium | O(n) | O(n) |
| 24 Swap Nodes in Pairs | Linked List | Easy | O(1) | O(n) |
| 61 Rotate List | Linked List | Medium | O(1) | O(N) |
| 83 Remove Duplicates From Sorted List | Linked List | Easy | O(1) | O(N) |
| 86 Partition List | Linked List | Medium | O(1) | O(N) |
| 141 Reorder List | Linked List | Medium | O(1) | O(N) |
| 206 Reverse LinkedList | Linked List | Easy | O(1) | O(N) |
| 445 Add Two Numbers II | Linked List | Medium | O(1) | O(N) |
DynamicProgramming(18)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 5 Longest Palindromic Substring | DP | Medium | O(n^2) | O(n^2) |
| 53 Maximum Subarray | DP | Medium | O(n) | O(n) |
| 55 Jump Game | DP | Medium | O(n) | O(n) |
| 62 Unique Paths | DP | Medium | O(mn) | O(mn) |
| 63 Unique Paths II | DP | Medium | O(mn) | O(mn) |
| 64 Minimum Path Sum | DP | Medium | O(mn) | O(mn) |
| 70 Climbing Stairs | DP | Easy | O(1) | O(N) |
| 72 Edit Distance | DP | Hard | O(NM) | O(NM) |
| 121 Best Time to Buy and Sell Stock | DP | Easy | O(1) | O(N) |
| 139 Word Break | DP | Medium | O(n) | O(nL^2) |
| 152 Maximum Product Subarray | DP | Medium | O(1) | O(n) |
| 198 House Robber | DP | Easy | O(n) | O(n) |
| 213 House Robber II | DP | Medium | O(n) | O(n) |
| 221 Maximal Square | DP | Medium | O(MN) | O(MN) |
| 279 Unique Paths II | DP | Medium | O(n) | O(n^2) |
| 300 Longest Increasing Subsequence | DP | Medium | O(n) | O(n^2) |
| 322 Coin Change | DP | Medium | O(n^2) | O(n) |
| 377 Combination Sum IV | Dynamic Programming | Medium | O(N) | O(n^(target/min(n))) |
Stack(7)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 20 Valid Parentheses | Stack | Easy | O(N) | O(N) |
| 94 Binary Tree In order Traversal | Stack | Medium | O(N) | O(N) |
| 144 Binary Tree Preorder Traversal | Stack | Medium | O(N) | O(N) |
| 145 Binary Tree Post Order Traversal | Stack | Hard | O(N) | O(N) |
| 224 Basic Calculator | Stack | Hard | O(N) | O(N) |
| 227 Basic Calculator II | Stack | Medium | O(N) | O(N) |
| 772 Basic Calculator III | Stack | Hard | O(N) | O(N) |
Heap(2)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 23 Merge K Sorted Lists | Heap | Hard | O(N) | O(Nlgk) |
| 295 Find Median From Data Stream | Heap | Hard | O(N) | O(1) |
Queue(1)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 346 Moving Average from Data Stream |
Queue | Easy | O(N) | O(1) |
Sort(3)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 75 Sort Colors | Sort | Medium | O(NlgN) | O(N) |
| 347 Top K Frequent Element | Sort | Medium | O(klgk) | O(N) |
| 56 Merge Intervals | Sort | Medium | O(NlgN) | O(N) |
DFS(8)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 46 Permutations | DFS | Medium | O(N!) | O(N!) |
| 47 Permutations II | DFS | Medium | O(N!) | O(N!) |
| 77 Combinations | DFS | Medium | O(N^K) | O(K*N^K) |
| 78 Subsets | DFS | Medium | O(2^N) | O(2^N) |
| 79 Word Search | DFS | Medium | O(3^N) | O(N^2) |
| 90 Subsets II | DFS | Medium | O(2^N) | O(2^N) |
| 212 Word Search II | DFS | Hard | O(N*3^N) | O(N^2) |
| 638 ShoppingOffers | DFS | Medium | O(N) | O(N^2) |
BFS(1)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 317 Shortest Distance from All Buildings |
BFS | Easy | O(MN) | O(KMN) |
Math(11)
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 7 Reverse Integer | Math | Easy | O(1) | O(1) |
| 8 String to Integer(atoi) | Math String | Easy | O(n) | O(1) |
| 9 Palindrome Number | Math | Easy | O(1) | O(1) |
| 136 Single Number | Math | Easy | O(1) | O(n) |
| 223 Rectangle Area | Math | Easy | O(1) | O(1) |
| 231 Power of Two | Math | Easy | O(1) | O(1) |
| 258 Add Digits | Math | Easy | O(1) | O(1) |
| 263 Ugly Number | Math | Easy | O(1) | O(1) |
| 326 Power of Three | Math | Easy | O(1) | O(1) |
| 338 Counting Bits | Math | Medium | O(N) | O(N) |
| 400 Nth Digit | Math | Easy | O(lgN) | O(1) |
[Google]
| Problem | Category | Difficulty | Space | Time |
|---|---|---|---|---|
| 294 Flip Game |
String | Medium | O(2^(n/2)) | O(2^(n/2)) |
| 308 Range Sum Query 2D - Mutable | Array | Hard | O(N^2) | O(N^2) |
| 317 Shortest Distance from All Buildings |
BFS | Easy | O(MN) | O(KMN) |
| 340 Longest SubString with At Most K Distinct Characters |
String | Hard | O(1) | O(N) |
| 346 Moving Average from Data Stream |
Queue | Easy | O(N) | O(1) |
| 361 Bomb Enemy |
Array | Medium | O(N) | O(MN) |
| 388 Longest Absolute File Path Solution | String | Medium | O(N) | O(N) |
| 394 Decode String | String | Medium | O(N) | O(N) |
| 418 Sentence Screen Fitting |
String | Medium | O(1) | O(row * col) |
| 482 LicenseKey Formatting Solution | String | Medium | O(n) | O(n) |