- Array
- Backtracking
- BFS
- BinarySearch
- BitManipulation
- Design
- DP
- DFS
- FenwickTree
- Greedy
- Graph
- Heap
- LinkedList
- Math
- Stack
- Sort
- String
- Tree
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 79. Word Search | Swift | Medium | O(mnl^4) | O(mn) |
| 17. Letter Combinations of a Phone Number | Swift | Medium | O(3^n * 4^m) | O(3^n * 4^m) |
| 47. Permutations II | Swift | Medium | O(n!) | O(n) |
| 46. Permutations | Swift | Medium | O(n!) | O(n!) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 102. Binary Tree Level Order Traversal | Swift | Medium | O(n) | O(n) |
| 103. Binary Tree Zigzag Level Order Traversal | Swift | Medium | O(n) | O(n) |
| 515. Find Largest Value in Each Tree Row | Swift | Medium | O(n) | O(n) |
| 515. Find Largest Value in Each Tree Row | Swift | Medium | O(n) | O(n) |
| 784. Letter Case Permutation | Swift | Medium | O(n * 2^n) | O(n * 2^n) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 33. Search in Rotated Sorted Array | Swift | Medium | O(logn) | O(1) |
| 153. Find Minimum in Rotated Sorted Array | Swift | Medium | O(logn) | O(1) |
| 704. Binary Search | Swift | Easy | O(logn) | O(1) |
| 744. Find Smallest Letter Greater Than Target | Swift | Easy | O(logn) | O(1) |
| 702. Search in a Sorted Array of Unknown Size | Swift | Medium | O(logT) | O(1) |
| 2187. Minimum Time to Complete Trips | Swift | Medium | O(nlogD) | O(1) |
| 2226. Maximum Candies Allocated to K Children | Swift | Medium | O(nlogD) | O(1) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 421. Maximum XOR of Two Numbers in an Array | Swift | Medium | O(n) | O(1) |
| 136. Single Number | Swift | Easy | O(n) | O(1) |
| 260. Single Number III | Swift | Medium | O(n) | O(1) |
| 832. Flipping an Image | Swift | Easy | O(n^2) | O(1) |
| 1009. Complement of Base 10 Integer | Swift | Easy | O(logN) | O(1) |
| 231. Power of Two | Swift | Easy | O(1) | O(1) |
| 371. Sum of Two Integers | Swift | Medium | O(1) | O(1) |
| 1371. Find the Longest Substring Containing Vowels in Even Counts | Swift | Medium | O(n) | O(1) |
| 1915. Number of Wonderful Substrings | Swift | Medium | O(n) | O(1) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 208. Implement Trie (Prefix Tree) | Swift | Medium | O(n) | O(n) |
| 146. LRU Cache | Swift | Medium | O(1) | O(n) |
| 295. Find Median from Data Stream | Swift | Hard | O(logn) | O(n) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 416. Partition Equal Subset Sum | Swift | Medium | O(mn) | O(m) |
| 64. Minimum Path Sum | Swift | Medium | O(mn) | O(1) |
| 96. Unique Binary Search Trees | Swift | Medium | O(n2) | O(n) |
| 309. Best Time to Buy and Sell Stock with Cooldown | Swift | Medium | O(n) | O(1) |
| 152. Maximum Product Subarray | Swift | Medium | O(n) | O(1) |
| 91. Decode Ways | Swift | Medium | O(n) | O(1) |
| 279. Perfect Squares | Swift | Medium | O(n√n) | O(n) |
| 1143. Longest Common Subsequence | Swift | Medium | O(nm) | O(nm) |
| 322. Coin Change | Swift | Medium | O(nm) | O(n) |
| 300. Longest Increasing Subsequence | Swift | Medium | O(nlogn) | O(n) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 200. Number of Islands | Swift | Medium | O(mn) | O(mn) |
| 257. Binary Tree Paths | Swift | Easy | O(n) | O(n) |
| 129. Sum Root to Leaf Numbers | Swift | Medium | O(n) | O(h) |
| 1430. Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree | Swift | Medium | O(n) | O(h) |
| 437. Path Sum III | Swift | Medium | O(n) | O(n) |
| 417. Pacific Atlantic Water Flow | Swift | Medium | O(mn) | O(mn) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 307. Range Sum Query - Mutable | Swift | Medium | O(nlogn) | O(n) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 621. Task Scheduler | Swift | Medium | O(n) | O(1) |
| 435. Non-overlapping Intervals | Swift | Medium | O(nlogn) | O(1) |
| 406. Queue Reconstruction by Height | Swift | Medium | O(n^2) | O(n) |
| Maximum Even Sum With K Number | Swift | Medium | O(nlogn) | O(n) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 133. Clone Graph | Swift | Medium | O(n + m) | O(n) |
| 261. Graph Valid Tree | Swift | Medium | O(n) | O(1) |
| 269. Alien Dictionary | Swift | Hard | O() | O() |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 1167. Minimum Cost to Connect Sticks | Swift | Medium | O(nlogn) | O(n) |
| 347. Top K Frequent Elements | Swift | Medium | O(n) | O(n) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 160. Intersection of Two Linked Lists | Swift | Easy | O(n + m) | O(1) |
| 203. Remove Linked List Elements | Swift | Easy | O(n) | O(1) |
| 141. Linked List Cycle | Swift | Easy | O(n) | O(1) |
| 142. Linked List Cycle II | Swift | Medium | O(n) | O(1) |
| 876. Middle of the Linked List | Swift | Easy | O(n) | O(1) |
| 234. Palindrome Linked List | Swift | Easy | O(n) | O(1) |
| 143. Reorder List | Swift | Medium | O(n) | O(1) |
| 92. Reverse Linked List II | Swift | Medium | O(n) | O(1) |
| 19. Remove Nth Node From End of List | Swift | Medium | O(n) | O(1) |
| 23. Merge k Sorted Lists | Swift | Hard | O(nlogk) | O(1) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 168. Excel Sheet Column Title | Swift | Easy | O(n) | O(1) |
| 171. Excel Sheet Column Number | Swift | Easy | O(n) | O(1) |
| 172. Factorial Trailing Zeroes | Swift | Easy | O(log5 n) | O(1) |
| 204. Count Primes | Swift | Easy | O(nlog log n) | O(n) |
| (時間複雜度很難算)202. Happy Number | Swift | Easy | O(logn) | O(1) |
| 50. Pow(x, n) | Swift | Medium | O(log n) | O(1) |
| 338. Counting Bits | Swift | Medium | O(n) | O(n) |
| 1823. Find the Winner of the Circular Game | Swift | Medium | O(n) | O(1) |
| 2141. Maximum Running Time of N Computers | Swift | Hard | O(nlogn) | O(1) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 394. Decode String | Swift | Medium | O(n) | O(n) |
| 20. Valid Parentheses | Swift | Easy | O(n) | O(n) |
| 84. Largest Rectangle in Histogram | Swift | Hard | O(n) | O(n) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 253. Meeting Rooms II | Swift | Medium | O(nlogn) | O(n) |
| Merge Sort | Swift | Medium | O(nlogn) | O(n) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 424. Longest Repeating Character Replacement | Swift | Medium | O(n) | O(1) |
| 290. Word Pattern | Swift | Easy | O(n) | O(m) |
| 76. Minimum Window Substring | Swift | Hard | O(S+T) | O(T) |
| 49. Group Anagrams | Swift | Medium | O(nk) | O(nk) |
| 647. Palindromic Substrings | Swift | Medium | O(n^2) | O(1) |
| 451. Sort Characters By Frequency | Swift | Medium | O(n) | O(n) |
| 763. Partition Labels | Swift | Medium | O(n) | O(1) |
| 1694. Reformat Phone Number | Swift | Easy | O(n) | O(n) |
| 224. Basic Calculator | Swift | Hard | O(n) | O(1) |
| 227. Basic Calculator II | Swift | Medium | O(n) | O(1) |
| 125. Valid Palindrome | Swift | Easy | O(n) | O(1) |
| 212. Word Search II | Swift | Hard | O() | O() |
| 271. Encode and Decode Strings | Swift | Medium | O(n) | O(1) |
| Title | Solution | Difficulty | Time | Space |
|---|---|---|---|---|
| 110. Balanced Binary Tree | Swift | Easy | O(n) | O(n) |
| 235. Lowest Common Ancestor of a Binary Search Tree | Swift | Easy | O(h) | O(1) |
| 105. Construct Binary Tree from Preorder and Inorder Traversal | Swift | Medium | O(n) | O(n) |
| 236. Lowest Common Ancestor of a Binary Tree | Swift | Medium | O(n) | O(n) |
| 111. Minimum Depth of Binary Tree | Swift | Easy | O(n) | O(n) |
| 98. Validate Binary Search Tree | Swift | Medium | O(n) | O(n) |
| 98. Validate Binary Search Tree | Swift | Medium | O(n) | O(n) |
| 112. Path Sum | Swift | Easy | O(n) | O(n) |
| 113. Path Sum II | Swift | Medium | O(n) | O(n) |
| 124. Binary Tree Maximum Path Sum | Swift | Hard | O(n) | O(h) |
| 572. Subtree of Another Tree | Swift | Easy | O(max(m,n)) | O(max(m,n)) |
| 297. Serialize and Deserialize Binary Tree | Swift | Hard | O(n) | O(n) |