JAVA作业——如何实现多线程抢红包

huatechinfo
发布于 2021-3-29 17:54
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大体思路
红包的分发见JAVA作业——红包分发。
而抢红包要解决的是线程问题。
其实比较简单,设定好人数,每个人一个线程,每个线程执行一遍,有红包就抢,没有红包就抢不到,所以run函数中只要判断现在还有没有红包就可以了。

代码实现

import java.util.Random;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int person_num, red_pocket_num, sum_money;
        Scanner scanner = new Scanner(System.in);
        System.out.println("请设置红包个数:");
        red_pocket_num = scanner.nextInt();
        System.out.println("请设置总金额数量(分):");
        sum_money = scanner.nextInt();
        if(sum_money < red_pocket_num) {
            System.out.println("钱不够,退出程序。");
            return;
        }
        System.out.println("请设置抢红包成员个数:");
        person_num = scanner.nextInt();
        myRunnable myrunnable = new myRunnable(sum_money,red_pocket_num);
        Thread []person = new Thread[person_num];
        for (int i = 0; i < person_num; i++) {
            person[i] = new Thread(myrunnable);
            person[i].setName("用户"+(i+1));
            person[i].start();
        }
    }
}
class myRunnable implements Runnable{
    private int []red_pocket;
    private int num;
    private int now_num;
    public myRunnable(int money, int num) {
        this.red_pocket = new Red_Pocket(money, num).get_red_packets();
        this.num = num;
        this.now_num = num;
    }
    @Override
    public void run() {
        if(this.num>0){
            System.out.println(Thread.currentThread().getName()+"抢到了红包 "+(this.num-this.now_num+1)+" : "+red_pocket[--this.now_num]+"分");
        }
        else{
            System.out.println(Thread.currentThread().getName()+"未抢到红包。");
        }
    }
}
class Red_Pocket{
    private long seed;
    private int money;
    private int num;
    public int[] get_red_packets() {
        if(this.money < this.num) return new int[0];
        Random random = new Random(this.seed);
        this.seed = random.nextLong();
        int[] res = new int[this.num];
        double[] temp = new double[this.num];
        double sum = 0;
        int sum2 = 0;
        for (int i = 0; i < this.num; i++) {
            temp[i] = random.nextDouble();
            sum += temp[i];
        }
        for (int i = 0; i < this.num; i++) {
            res[i] = 1 + (int)(temp[i] / sum * (this.money - this.num));
            sum2 += res[i];
        }
        res[random.nextInt(this.num)] += this.money - sum2;
        return res;
    }
    private void init() {
        this.seed = new Random(System.currentTimeMillis()).nextLong();
    }
    public Red_Pocket(int money,int num) {
        init();
        this.money = money;
        this.num = num;
    }
}


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版权声明:本文为博主「Evrse」的原创文章

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