按照单词的字母是否相同对字符串数组进行分组

左手的ㄟ右手 2022-05-13 06:50 203阅读 0赞

[https://blog.csdn.net/Lynn\_Baby/article/details/80790796][https_blog.csdn.net_Lynn_Baby_article_details_80790796]

**题目描述：**

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

Note: All inputs will be in lower-case.

**思路解析：**

1.首先判空  
2.创建元素类型为ArrayList（String）的ArrayList作为结果res，创建元素类型为（String，ArrayList(String)）的HashMap  
3.遍历strs，把每个字符串Arrays.sort以后，再分组存入HashMap  
4.遍历HashMap的values,存入res，返回res

**代码：**

public static void main(String[] args) throws IOException {
            String[] strs = {
       "a","acb","bca","aabcd","abcdefgh","abdca"};
            ArrayList<ArrayList<String>> res = anagrams(strs);
            System.out.println(res);
            //[[acb, bca], [aabcd, abdca], [a], [abcdefgh]]
    
    }
        //按照单词的字母是否相同对字符串数组进行分组
        public static ArrayList<ArrayList<String>> anagrams(String[] strs) {
            ArrayList<ArrayList<String>> res = new ArrayList<ArrayList<String>>();
            if(strs==null || strs.length==0){
                return res;
            }
            HashMap<String,ArrayList<String>> hm = new HashMap<String,ArrayList<String>>();
            for(String s : strs){
                char[] ch = s.toCharArray();
                Arrays.sort(ch);
                String temp = new String(ch);
                if(hm.containsKey(temp)){
                   hm.get(temp).add(s);
                   hm.put(temp, hm.get(temp));
    
                }else{
                    ArrayList<String> templist = new ArrayList<String>();
                    templist.add(s);
                    hm.put(temp,templist);
                }
            }
            Collection<ArrayList<String>> values=hm.values();
            for(Iterator it=values.iterator();it.hasNext();){
                res.add((ArrayList<String>)it.next());
            }
            return res;
        }

[https_blog.csdn.net_Lynn_Baby_article_details_80790796]: https://blog.csdn.net/Lynn_Baby/article/details/80790796