java实现抢红包算法（公平版和手速版）

public static List<Double> doubleMeanMethod(double money,int number){
 List<Double> result = new ArrayList<Double>();
 if(money<0&&number<1)
 return null;
 double amount,sum=0;
 int remainingNumber=number;
 int i=1;
 while(remainingNumber>1){
 amount= nextDouble(0.01,2*(money/remainingNumber));
 sum+=amount;
 System.out.println("第"+i+"个人领取的红包金额为："+format(amount));
 money -= amount;
 remainingNumber--;
 result.add(amount);
 i++;
 }
 result.add(money);
 System.out.println("第"+i+"个人领取的红包金额为："+format(money));
 sum+=money;
 System.out.println("验证发出的红包总金额为："+format(sum));
 
 return result;
 
 
 }

public static void lineSegmentCutting(double money,int number){
 if(money<0&&number<1)
 System.out.println("输入错误！");
 double begin=0,end=money;
 double y=0;
 for(int i=0;i<number-1;i++){
 double nn=0;
 double amount=nextDouble(begin,end);
 
 nn=amount-begin;
 System.out.println("第"+(i+1)+"个人领取的红包金额为："+format(nn));
 y+=nn;
 begin=amount;
 
 }
 System.out.println("第"+number+"个人领取的红包金额为："+format(end-begin));
 y+=(end-begin);
 System.out.println("验证发出的红包总金额为："+format(y));
 
}

package com.zhl.blogTest;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.Scanner;

public class redEnvelope {
 
 /*Random 随机生成一个区间在[min , max]的数值
 randNumber 将被赋值为一个 MIN 和 MAX 范围内的随机数
 int randNumber =rand.nextInt(MAX - MIN + 1) + MIN; */
 
 

 /**
 * 生成min到max范围的浮点数
 **/
 public static double nextDouble(final double min, final double max) {
 return min + ((max - min) * new Random().nextDouble());
 }
 
 public static String format(double value) {
 
 return new java.text.DecimalFormat("0.00").format(value); // 保留两位小数
 }
 

 //二倍均值法
 public static List<Double> doubleMeanMethod(double money,int number){
 List<Double> result = new ArrayList<Double>();
 if(money<0&&number<1)
 return null;
 double amount,sum=0;
 int remainingNumber=number;
 int i=1;
 while(remainingNumber>1){
 amount= nextDouble(0.01,2*(money/remainingNumber));
 sum+=amount;
 System.out.println("第"+i+"个人领取的红包金额为："+format(amount));
 money -= amount;
 remainingNumber--;
 result.add(amount);
 i++;
 }
 result.add(money);
 System.out.println("第"+i+"个人领取的红包金额为："+format(money));
 sum+=money;
 System.out.println("验证发出的红包总金额为："+format(sum));
 
 return result;
 
 
 }
 
 //线段切割法
 public static void lineSegmentCutting(double money,int number){
 if(money<0&&number<1)
 System.out.println("输入错误！");
 double begin=0,end=money;
 double y=0;
 for(int i=0;i<number-1;i++){
 double nn=0;
 double amount=nextDouble(begin,end);
 
 nn=amount-begin;
 System.out.println("第"+(i+1)+"个人领取的红包金额为："+format(nn));
 y+=nn;
 begin=amount;
 
 }
 System.out.println("第"+number+"个人领取的红包金额为："+format(end-begin));
 y+=(end-begin);
 System.out.println("验证发出的红包总金额为："+format(y));
 
 }
 
 public static void main(String[] args) {
 Scanner sc = new Scanner(System.in);
 System.out.println("这是一段模拟抢红包的代码。");
 
 int number;
 double money;
 System.out.print("请输入红包总金额：");
 money = sc.nextDouble();
 System.out.print("请输入红包数量：");
 number = sc.nextInt();
 //System.out.println(money + " " + number);
 
 //二倍均值法
 doubleMeanMethod(money,number);
 //System.out.println(doubleMeanMethod(money,number).toString());
 //也是可以直接输出list的，为了观察方便，我就在循环中输出了，存在list里主要是为了后续方便数据的使用
 System.out.println();
 
 //线段切割法
 lineSegmentCutting(money,number);
 

 }

}