编辑代码

import java.util.*;
class Main {
	public static void main(String[] args) {
        Map<String,String> map = new HashMap<>();
        vote(map,"张三","A");
        vote(map,"李四","A");
        vote(map,"张三","B");
        vote(map,"王五","A");
        vote(map,"张三","B");
	}
    public static void vote(Map<String,String> map,String name,String voteName){
        // 判断map中是否存在name键，如果存在则退出，否则将该信息添加进map中
        if(map.containsKey(name)){
            System.out.println("请勿重复投票！");
        }else{
           map.put(name,voteName);
           System.out.println(name+",投票成功！");
        }
    }
}