Java Map集合类案例，统计投票票数

import java.util.HashMap;
import java.util.Map;
import java.util.Random;

public class Demon {
    public static void main(String[] args) {
        //统计100个人的投票数
        String[] select={"A","B","C","D"};
        StringBuilder sh=new StringBuilder();
        Random r=new Random();
        for (int i = 0; i <100 ; i++) {//模拟投票
            sh.append(select[r.nextInt(select.length)]);
        }
        System.out.println(sh);
        //定义一个Map集合：键是 select={"A","B","C","D"}，值是投票数量
        Map res=new HashMap<>();
        //遍历100个人投票结果
        for (int i = 0; i