快手[编程题] 字符串归一化

每个测试用例每行为一个字符串，以'\n'结尾，例如cccddecca

输出压缩后的字符串ac5d2e

dabcab

a2b2c1d1

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String s = in.next();
        Map map=new HashMap();
        for(int i=0;i<s.length();i++){
            char ch=s.charAt(i);
            if(map.get(ch)==null){
                map.put(ch,1);
            }else{
                int cnt= (int) map.get(ch);
                map.put(ch,cnt+1);
            }
        }
        for(Object obj : map.entrySet()){
            Map.Entry<String,Integer> entry= (Map.Entry<String, Integer>) obj;
            System.out.print(String.valueOf(entry.getKey())+ entry.getValue());
        }
        in.close();
    }
}