java抽奖系统的设计(java抽奖程序代码)
奖品类：
抽奖逻辑：
测试类：
测试结果：
商品类：
package org.plusgroup.modules.app.controller.vo;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import java.util.ArrayList;
import java.util.List;
/**
* @author Administrator
* @desc 奖品VO
* @date 2021/7/9 14:30
*/
@Data
public class PrizeVo {
@ApiModelProperty("奖品ID")
private Integer id;
@ApiModelProperty("奖品名称")
private String name;
@ApiModelProperty("奖品编号")
private String code;
@ApiModelProperty("中奖概率")
private Double rate;
public PrizeVo(Integer id, String name, String code, Double rate) {
this.id = id;
this.name = name;
this.code = code;
this.rate = rate;
}
public PrizeVo() {
}
/**
* 初始化奖品
* @return List
*/
public static List<PrizeVo> init(){
List<PrizeVo> list = new ArrayList<>();
list.add(new PrizeVo(10, "文档打印券", "P1", 0.2d));
list.add(new PrizeVo(20, "照片打印券", "P2", 0.5d));
list.add(new PrizeVo(30, "5元代金券", "P3", 0.1d));
list.add(new PrizeVo(40, "谢谢参与", "P4", 0.2d));
return list;
}
}
测试类：
package org.plusgroup.modules.admin.service;
import org.plusgroup.modules.app.controller.vo.PrizeVo;
import org.springframework.util.CollectionUtils;
import java.util.*;
/**
* @author Administrator
* @desc
* @date 2021/7/9 14:43
*/
public class IntegralLogTest {
public static void main(String [] args){
//奖品中奖概率集合
List<Double> rates = new ArrayList<>();
//将每个奖品的概率放入概率集合
List<PrizeVo> list = PrizeVo.init();
for(PrizeVo prizeVo : list){
rates.add(prizeVo.getRate());
}
System.out.println("本次中奖商品下标:" +luckDraw(rates));
// 统计每种商品中奖次数
Map<Integer, Integer> countMap = new HashMap<>();
double num = 10000; //测试次数
for (int i = 0; i < num; i++) {
int key = luckDraw(rates);
Integer value = countMap.get(key);
countMap.put(key, value == null ? 1 : value + 1);
}
for (Map.Entry<Integer, Integer> entry : countMap.entrySet()) {
System.out.println(list.get(entry.getKey()) + ", 命中次数=" + entry.getValue() + ", 实际概率=" + entry.getValue() / num);
}
}
/**
* 抽奖逻辑
* @param rates 概率集合
* @return int
*/
public static int luckDraw(List<Double> rates) {
if (CollectionUtils.isEmpty(rates)) {
return -1;
}
//计算总概率，概率集合累加
double totalRate = 0d;
for (double rate : rates) {
totalRate += rate;
}
// 每个奖品在总概率基础下的概率
List<Double> sortRates = new ArrayList<>();
double everyRate = 0d;
for (double rate : rates) {
everyRate += rate;
sortRates.add(everyRate / totalRate);
}
// 根据区块值来获取抽取到的物品索引
double nextDouble = Math.random();
sortRates.add(nextDouble);
Collections.sort(sortRates);
return sortRates.indexOf(nextDouble);
}
}
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