Given an array of strings, return all groups of strings that are anagrams.

Note: All inputs will be in lower-case.

思路：anagram的题目，CC150也有，如何判断是anagram，一种是用hashmap存字符数来判断，另一种是排序后字符相同来判断。这个题目采用排序后的字符作为hashmap的key，是anagram的都归为一组。

import java.util.ArrayList;import java.util.Arrays;import java.util.HashMap;public class Solution {	public ArrayList
    
      anagrams(String[] strs) {		if (strs == null)			return null;		ArrayList
     
       res = new ArrayList
      
       ();		HashMap
       
        > group = new HashMap
        
         >();		for (String each : strs) {			char[] tmp = each.toCharArray();			Arrays.sort(tmp);			String key = new String(tmp);			if (group.containsKey(key)) {				group.get(key).add(each);			} else {				ArrayList
         
           newList = new ArrayList
          
           (); newList.add(each); group.put(key, newList); } } for (String each : group.keySet()) { if (group.get(each).size() > 1) { res.addAll(group.get(each)); } } return res; } public static void main(String[] args) { System.out.println(new Solution().anagrams(new String[] { "abc", "acb", "cba", "aaa", "bb", "bb" })); }}
          
         
        
       
      
     
    

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