抢红包架构设计抢红包实现方案

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云端小悟空 2023-07-06 10:40:34

文章标签 抢红包架构设计 java List System 文章分类 架构后端开发

算法原理

今天分享一篇有趣的抢红包算法，基本原理就是“二倍均值”，简单说，也就是一个公式，在这里，令P为人数，M为红包总金额，那么每次抢到的红包金额=随机区间（0，P/Mx2），这样才可以保证每次抢到随机金额的均值是相等的。

代码展示

1 package Sort_normal;
 2 
 3 import java.math.BigDecimal;
 4 import java.util.ArrayList;
 5 import java.util.List;
 6 import java.util.Random;
 7 import java.util.Scanner;
 8 
 9 // M:剩餘紅包
10 // N:剩餘金額
11 // 每次搶到金額：隨機區間[0,M/Nx2]
12 public class Red_Package {
13     public static void main(String[] args) {
14         Scanner in = new Scanner(System.in);
15         System.out.println("请输入红包金额：");
16         Integer TotalAmount = in.nextInt();
17         System.out.println("请输入人数：");
18         Integer TotalPeople = in.nextInt();
19         List<Integer> amountList = RedPackage(TotalAmount, TotalPeople);
20 //        String[] NameList = new String[]{"小黄", "张三", "李四", "王五", "鹤叔", "丽丽", "小明", "阿杰", "媚姐", "王姨"};
21         for (Integer amount : amountList) {
22             System.out.println("搶到金額：" + new BigDecimal(amount).divide(new BigDecimal(100)) + "元");
23         }
24     }
25 
26     public static List<Integer> RedPackage(Integer TotalAmount, Integer TotalPeople) {
27         List<Integer> amountList = new ArrayList<Integer>();
28         Integer restAmount = TotalAmount;//剩餘金額
29         Integer restPeople = TotalPeople;//剩餘人數
30         Random random = new Random();
31         for (int i = 0; i < TotalPeople - 1; i++) {
32             //隨機範圍：[1,剩餘人均金額的兩倍]
33             int amount = random.nextInt(restAmount / restPeople * 2 - 1) + 1;
34             restAmount -= amount;
35             restPeople--;
36             amountList.add(amount);
37         }
38         amountList.add(restAmount);
39         return amountList;
40     }
41 }