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

Note: All inputs will be in lower-case.

https://oj.leetcode.com/problems/anagrams/

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<String> anagrams(String[] strs) {		if (strs == null)			return null;		ArrayList<String> res = new ArrayList<String>();		HashMap<String, ArrayList<String>> group = new HashMap<String, ArrayList<String>>();		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<String> newList = new ArrayList<String>();				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" }));	}}

参考：

http://blog.csdn.net/linhuanmars/article/details/21664747