Solution for String

#	Name	Difficulty	Tags
3	Longest Substring Without Repeating Characters	Medium	Hash Table | Two Pointers | String | Sliding Window
5	Longest Palindromic Substring	Medium	Dynamic Programming | String
6	ZigZag Conversion	Medium	String
8	String to Integer (atoi)	Medium	Math | String
10	Regular Expression Matching	Hard	String | Dynamic Programming | Backtracking
12	Integer to Roman	Medium	Math | String
13	Roman to Integer	Easy	Math | String
14	Longest Common Prefix	Easy	String
17	Letter Combinations of a Phone Number	Medium	String | Backtracking | Depth-first search | Recursion
20	Valid Parentheses	Easy	String | Stack
22	Generate Parentheses	Medium	String | Backtracking
28	Implement strStr()	Easy	Two Pointers | String
30	Substring with Concatenation of All Words	Hard	Hash Table | Two Pointers | String
32	Longest Valid Parentheses	Hard	String | Dynamic Programming
38	Count and Say	Medium	String
43	Multiply Strings	Medium	Math | String
44	Wildcard Matching	Hard	String | Dynamic Programming | Backtracking | Greedy
58	Length of Last Word	Easy	String
126	Word Ladder II	Hard	Array | String | Backtracking | Breadth-first Search
536	Construct Binary Tree from String	Medium	String | Tree
606	Construct String from Binary Tree	Easy	String | Tree
1268	Search Suggestions System	Medium	String
1297	Maximum Number of Occurrences of a Substring	Medium	String | Bit Manipulation
1332	Remove Palindromic Subsequences	Easy	String
1347	Minimum Number of Steps to Make Two Strings Anagram	Medium	String
1374	Generate a String With Characters That Have Odd Counts	Easy	String
1736	Latest Time by Replacing Hidden Digits	Easy	String | Greedy
1737	Change Minimum Characters to Satisfy One of Three Conditions	Medium	String | Greedy
1759	Count Number of Homogenous Substrings	Medium	String | Greedy
1763	Longest Nice Substring	Easy	String
1768	Merge Strings Alternately	Easy	String