LeetCode (Notes: "♥" means you need buy a book from Leetcode) # Title Solution Difficulty 1 Two Sum JavaScript Easy 2 Add Two Numbers JavaScript Medium 3 Longest Substring JavaScript Medium 5 Longest Palindromic JavaScript Medium 6 ZigZag Conversion JavaScript Easy 7 Reverse Integer JavaScript Easy 8 String to Integer (atoi) JavaScript Easy 9 Palindrome Number JavaScript Easy 11 Container With Most Water JavaScript Medium 12 Integer to Roman JavaScript Medium 13 Roman to Integer JavaScript Easy 14 Longest Common Prefix JavaScript Easy 15 3Sum JavaScript Medium 16 3Sum_Closest JavaScript Medium 17 Letter Combinations of a Phone Number JavaScript Medium 18 4Sum JavaScript Medium 19 Remove Nth Node From End of List JavaScript Easy 20 Valid Parentheses JavaScript Easy 21 Merge Two Sorted Lists JavaScript Easy 22 Generate Parentheses JavaScript Medium 24 Swap Nodes in Pairs JavaScript Easy 26 Remove Duplicates from Sorted Array JavaScript Easy 27 Remove Element JavaScript Easy 28 Implement strStr() JavaScript Easy 29 Divide Two Integers JavaScript Medium 31 Next Permutation JavaScript Medium 34 Search for a Range JavaScript Medium 35 Search Insert Position JavaScript Medium 36 Valid Sudoku JavaScript Easy 38 Count and Say JavaScript Easy 39 Combination Sum JavaScript Medium 40 Combination Sum II JavaScript Medium 43 Multiply Strings JavaScript Medium 46 Permutations JavaScript Medium 47 Permutations II JavaScript Medium 48 Rotate Image JavaScript Medium 49 Group Anagrams JavaScript Medium 50 Pow(x, n) JavaScript Medium 51 N-Queens JavaScript Hard 53 Maximum Subarray JavaScript Easy 54 Spiral Matrix JavaScript Medium 55 Jump Game JavaScript Medium 56 Merge Intervals JavaScript Medium 69 Sqrt(x) JavaScript Easy 371 Sum of Two Integers JavaScript Easy 372 Super Pow JavaScript Medium