LeetCode LeetCode Algorithm # Title Solution Difficulty 1 Two Sum JS, Java Easy 2 Add Two Numbers JS, Java Medium 3 Longest Substring Without Repeating Characters JS, Java Medium 4 Median of Two Sorted Arrays JS, Java Hard 5 Longest Palindromic Substring JS, Java Medium 6 ZigZag Conversion JS, Java Medium 7 Reverse Integer JS, Java Easy 8 String to Integer (atoi) JS, Java Medium 9 Palindrome Number JS, Java Easy 11 Container With Most Water JS, Java Medium 12 Integer to Roman JS, Java Medium 13 Roman to Integer JS, Java Easy 14 Longest Common Prefix JS, Java Easy 15 3Sum JS, Java Medium 16 3Sum Closest JS, Java Medium 17 Letter Combinations of a Phone Number JS, Java Medium 18 4Sum JS, Java Medium 19 Remove nth node from end of list JS, Java Medium 20 Valid Parentheses JS, Java Easy 21 Merge Two Sorted Lists JS, Java Easy 22 Generate Parentheses JS, Java Medium 23 Merge K Sorted Lists JS, Java Hard 24 Swap Nodes in Pairs JS, Java Medium 26 Remove Duplicates from Sorted Array JS, Java Easy 27 Remove Element JS, Java Easy 28 Implement strStr() JS, Java Easy 30 Substring with Concatenation of All Words JS, Java Hard 31 Next Permutation JS, java Medium 33 Search in Rotated Sorted Array JS, java Medium 34 Find First and Last Position of Element in Sorted Array JS, java Medium 35 Search Insert Position JS, Java Easy 36 Valid Sudoku JS, Java Medium 38 Count and Say JS, Java Easy 39 Combination Sum JS, Java Meidum 48 Rotate Image JS, Java Medium 53 Maximum Subarray JS, Java Easy 54 Spiral Matrix JS, Java Medium 58 Length of Last Word JS, Java Easy 66 Plus One JS, Java Easy 67 Add Binary JS, Java Easy 70 Climbing Stairs JS, Java Easy 75 Sort Colors JS, Java Medium 80 Remove Duplicates from Sorted Array II JS, Java Medium 88 Merge Sorted Array JS easy 122 Best Time to Buy and Sell Stock II JS, Java Easy 125 Valid Palindrome JS, Java Easy 136 Single Number JS, Java Easy 167 Two Sum II - Input array is sorted Java Easy 189 Rotate Array JS, Java Easy 206 Reverse Linked List JS, Java Easy 215 Kth Largest Element in an Array Java Easy 217 Contains Duplicate JS, Java Easy 234 Palindrome Linked List JS, Java Easy 237 Delete Node in a Linked List JS, Java Easy 242 Valid Anagram JS, Java Easy 283 Move Zeroes JS, Java Easy 344 Reverse String JS, Java Easy 350 Intersection of Two Arrays II JS, Java Easy 387 First Unique Character in a String JS, Java Easy 724 Find Pivot Index JS, Java Easy 747 Largest Number At Least Twice of Others JS, Java Easy 498 Diagonal Traverse JS, Java Medium