# Title Solution 1 Two Sum Python 2 Add Two Numbers Python 3 Longest Substring Without Repeating Characters Python 4 Median of Two Sorted Arrays Python 5 Longest Palindromic Substring Python 6 https://leetcode.com/problems/zigzag-conversion/ Python 7 Reverse Integer Python 8 String to Integer (atoi) Python 9 Palindrome Number Python 10 Regular Expression Matching Python 11 Container With Most Water Python 12 Integer to Roman Python 13 Roman to Integer Python 14 Longest Common Prefix Python 15 3Sum Python 16 3Sum Closest Python 17 Letter Combinations of a Phone Number Python 20 valid-parentheses Python 20 merge-two-sorted-lists Python 22 generate-parentheses Python 23 merge-k-sorted-lists Python 23 swap-nodes-in-pairs Python 25 reverse-nodes-in-k-group Python 27 remove-element Python 112 Path Sum Python 153 Find Minimum in Rotated Sorted Array Python 169 majority element Python 290 Word Pattern Python 319 Bulb Switcher Python 330 patching-array Python