import java.util.ArrayList;

/**
 * 群主类
 */
public class Manager extends User {
    public Manager() {
    }

    public Manager(int money, String name) {
        super(money, name);
    }
    public ArrayList<Integer> send(int totalMoney,int count){
        //先创一个集合，把红包放入集合。
        ArrayList<Integer> redllist = new ArrayList<>();
        //首先查看一下群主有多少钱
        int lifeMoney = super.getMoney();
        //发红包的钱不能超过群主原有的金钱
        if (totalMoney > lifeMoney){
            System.out.println("余额不足。");
            return redllist;//返回一个空集合
        }
        //扣钱其实就是重新设置金额把剩余的钱放回去
        super.setMoney(lifeMoney-totalMoney);//好像写于不写没差别

        //发红包要平均分成count份
        int avg = totalMoney / count;
        int dae = totalMoney % count;//余下的零头

        //除不开的零头放到最后一个红包中
        //下面把红包一个一个放到红包当中
        for (int i = 0; i < count-1; i++) {
            redllist.add(avg);

        }
        //最后一个红包
        int last = avg + dae;
        redllist.add(last);

        return redllist;

    }
}

?

import java.util.ArrayList;
import java.util.Random;

public class Number extends User {
    public Number() {
    }

    public Number(int money, String name) {
        super(money, name);
    }
    public void  receive(ArrayList<Integer> list){

        //从多个红包中随机抽取一个，给我自己。
        //随机获取一个集合当中的几何编号
        int index = new Random().nextInt(list.size());
        //根据索引，从集合中删除，并找到删除的红包，给自己
        int sd = list.remove(index);
        //当前成员自己本来有多少钱
        int money = super.getMoney();
        //加法，并重新设置回去
        super.setMoney(money + sd);
    }
}

import asd.demo06.Manage;

import java.util.ArrayList;

public class test {
    public static void main(String[] args) {
        Manage manage = new Manage("胡总",100);

       Number one = new Number(0,"成员A");
       Number two = new Number(0,"成员B");
       Number three = new Number(0,"成员C");

        manage.show();
        one.show();
        two.show();
        three.show();
        System.out.println("=====================");
        ArrayList<Integer> list = manage.send(20,3);

        one.receive(list);
        two.receive(list);
        three.receive(list);

        manage.show();
        one.show();
        two.show();
        three.show();
    }
}