[leetcode] Anagrams

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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的題目，CC150也有，如何判斷是anagram，一種是用hashmap存字元數來判斷，另一種是排序後字元相同來判斷。這個題目採用排序後的字元作為hashmap的key，是anagram的都歸為一組。

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" }));}}

參考：

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