LeetCode Solutions # Problem Tutorial Code Time Space 1 Two Sum Tutorial Code O(n) O(n) 3 Longest Substring Without Repeating Characters Tutorial Code O(n) O(1) 15 3Sum Tutorial Code O(n²) O(1) 39 Combination Sum Tutorial Code O(|c| x t) O(n) 40 Combination Sum II Tutorial Code O(|c| x t) O(n) 49 Group Anagrams Tutorial Code * * 55 Jump Game Tutorial Code O(n) O(1) 56 Merge Intervals Tutorial Code O(nlogn) O(1) 57 Insert Interval Tutorial Code O(n) O(1) 70 Climbing Stairs Tutorial Code O(n) O(1) 74 Search a 2D Matrix Tutorial Code $O(\log n)$ O(1) 91 Decode Ways Tutorial Code O(n) O(1) 104 Maximum Depth of Binary Tree Tutorial Code O(n) O(n) 121 121. Best Time to Buy and Sell Stock Tutorial Code O(n) O(1) 128 Longest Consecutive Sequence Tutorial Code O(n) O(n) 141 Linked List Cycle Tutorial Code O(n) O(1) 153 Find Minimum in Rotated Sorted Array Tutorial Code O(log n) O(1) 167 Two Sum II - Input Array Is Sorted Tutorial Code O(n) O(1) 198 House Robber Tutorial Code O(n) O(1) 208 Implement Trie (Prefix Tree) Tutorial Code * * 211 Design Add and Search Words Data Structure Tutorial Code * * 213 House Robber II Tutorial Code O(n) O(1) 216 Combination Sum III Tutorial Code O(n) O(n) 217 Contains Duplicate Tutorial Code O(n) O(n) 226 Invert Binary Tree Tutorial Code O(n) O(n) 238 Product of Array Except Self Tutorial Code O(n) O(1) 240 Search a 2D Matrix II Tutorial Code $O(r + c)$ $O(1)$ 242 Valid Anagram Tutorial Code O(n) O(1) 297 Serialize and Deserialize Binary Tree Tutorial Code O(n) O(n) 322 Coin Change Tutorial Code O(|coins| * amount) O(amount) 347 Top K Frequent Elements Tutorial Code O(n) O(n) 377 Combination Sum IV Tutorial Code O(n) O(n) 424 Longest Repeating Character Replacement Tutorial Code O(n) O(1) 435 Non-overlapping Intervals Tutorial Code O(nlogn) O(1) 572 Subtree of Another Tree Tutorial Code O(|s| x |t|) O(1) 647 Palindromic Substrings Tutorial Code O(n²) O(1) 714 Best Time to Buy and Sell Stock with Transaction Fee Tutorial Code O(n) O(1) 1325 Delete Leaves With a Given Value Tutorial Code $O(n)$ $O(1)$
