LeetCode LeetCode Algorithm # Title and Description Solution 1 Two Sum Two Sum C# Solution 9 Palindrome Number Palindrome Number C# Solution 13 Roman to Integer Roman to Integer C# Solution 20 Valid Parentheses Valid Parentheses C# Solution 26 Remove Duplicates from Sorted Array Remove Duplicates from Sorted Array C# Solution 27 Remove Element Remove Element C# Solution 55 Jump Game Jump Game C# Solution 58 Length of Last Word Length of Last Word C# Solution 80 Remove Duplicates from Sorted Array II Remove Duplicates from Sorted Array II C# Solution 121 Best Time to Buy and Sell Stock Best Time to Buy and Sell Stock C# Solution 122 Best Time to Buy and Sell Stock II Best Time to Buy and Sell Stock II C# Solution 125 Valid Palindrome Valid Palindrome C# Solution 169 Majority Element Majority Element C# Solution 189 Rotate Array Rotate Array C# Solution 202 Happy Number Happy Number C# Solution 219 Contains Duplicate II Contains Duplicate II C# Solution 228 Summary Ranges Summary Ranges C# Solution 242 Valid Anagram Valid Anagram C# Solution 260 Single Number III Single Number III C# Solution 344 Reverse String Reverse String C# Solution 383 Ransom Note Ransom Note C# Solution 392 Is Subsequence Is Subsequence C# Solution 2486 Append Characters to String to Make Subsequence Append Characters to String to Make Subsequence C# Solution