LeetCode Solved problems # Title Solution Difficulty 1 Two Sum C++ Easy 2 Add Two Numbers C++ Medium 3 Longest Substring Without Repeating Characters C++ Medium 4 Median of Two Sorted Arrays C++ Hard 6 Zigzag Conversion C++ Medium 7 Reverse Integer C++ Medium 9 Palindrome Number C++ Easy 19 Remove Nth Node From End of List C++ Medium 21 Merge Two Sorted Lists C++ Easy 23 Merge k Sorted Lists C++ Hard 25 Reverse Nodes in k-Group C++ Hard 33 Search in Rotated Sorted Array C++ Medium 34 Find First and Last Position of Element in Sorted Array C++ Medium 35 Search Insert Position C++ Easy 41 First Missing Positive C++ Hard 62 Unique Paths C++ Medium 69 Sqrt(x) C++ Easy 94 Binary Tree Inorder Traversal C++ Easy 108 Convert Sorted Array to Binary Search Tree C++ Easy 167 Two Sum II - Input Array Is Sorted C++ Medium 189 Rotate Array C++ Medium 206 Reverse Linked List C++ Easy 217 Contains Duplicate C++ Easy 235 Lowest Common Ancestor of a Binary Search Tree C++ Easy 278 First Bad Version C++ Easy 283 Move Zeroes C++ Easy 344 Reverse String C++ Easy 349 Intersection of Two Arrays C++ Easy 350 Intersection of Two Arrays II C++ Easy 367 Valid Perfect Square C++ Easy 374 Guess Number Higher or Lower C++ Easy 377 Combination Sum IV C++ Medium 378 Kth Smallest Element in a Sorted Matrix C++ Medium 392 Is Subsequence C++ Easy 393 UTF-8 Validation C++ Medium 429 N-ary Tree Level Order Traversal C++ Medium 441 Arranging Coins C++ Easy 520 Detect Capital C++ Easy 557 Reverse Words in a String III C++ Easy 606 Construct String from Binary Tree C++ Easy 637 Average of Levels in Binary Tree C++ Easy 704 Binary Search C++ Easy 705 Design HashSet C++ Easy 706 Design HashMap C++ Easy 729 My Calendar I C++ Medium 858 Mirror Reflection C++ Medium 876 Middle of the Linked List C++ Easy 944 Delete Columns to Make Sorted C++ Easy 948 Bag of Tokens C++ Medium 977 Squares of a Sorted Array C++ Easy 987 Vertical Order Traversal of a Binary Tree C++ Hard 1457 Pseudo-Palindromic Paths in a Binary Tree C++ Medium 1770 Maximum Score from Performing Multiplication Operations C++ Medium 1962 Remove Stones to Minimize the Total C++ Medium 1996 The Number of Weak Characters in the Game C++ Medium 2007 Find Original changedrray From Doubled changedrray C++ Medium 2244 Minimum Rounds to Complete All Tasks C++ Medium