49. Group Anagrams

Input: [“eat”, “tea”, “tan”, “ate”, “nat”, “bat”],
Output:
[
[“ate”,“eat”,“tea”],
[“nat”,“tan”],
[“bat”]
]
這道題主要用到了HashMap的例子

class Solution {
	public List<List<String>> groupAnagrams(String[] strs) {
		HashMap<String,List<String>> hm = new HashMap
 
<String,List<String>>();
		List<List<String>> res=new ArrayList<List<String>>();
		for (String str:strs) {
			char[] ch=str.toCharArray();
			Arrays.sort(ch);
			String sorted=new String(ch);
			if(hm.containsKey(sorted)){
				hm.get(sorted).add(str);
			}else {
				List<
 
String> list=new ArrayList<String>();
				list.add(str);
				hm.put(sorted, list);
			}
		}
		res.addAll(hm.values());
		return res;
	}
}