Java第六次作业

关于抽奖系统的程序如下：

import java.util.HashSet;
import java.util.Iterator;
import java.util.Random;
import java.util.Scanner;

public class choujiang {
    private HashSet<Integer>set;
    private Random rand;
    private Scanner sc;
    
    public choujiang(){
        set = new HashSet<>();
        rand = new Random();
        sc = new Scanner(System.in);
    }
    
    public void addToSte(){
        System.out.println("~~欢迎大家参与本次抽奖活动~~");
        System.out.println("~~本活动上限人数：1000人~~");
        System.out.println("请输入总奖品数目：");
        int total = sc.nextInt();
        while(set.size()<total){
            set.add(rand.nextInt(1000));
        }
    }
    
    public void drawPrize(){
        System.out.println("分别按顺序输入一、二、三等奖的获奖人数：");
        int prize1 = sc.nextInt();
        int prize2 = sc.nextInt();
        int prize3 = sc.nextInt();
        Iterator iterator = set.iterator();
        
        int i =0;
        System.out.println("~~恭喜以下参与者获得一等奖~~");
        while(i<prize1){
            System.out.println("参与者号码:"+iterator.next());
            iterator.remove();
            i++;
        }
        
        i=0;
        System.out.println("~~恭喜以下参与者获得二等奖~~");
        while(i<prize2){
            System.out.println("参与者号码:"+iterator.next());
            iterator.remove();
            i++;
        }
        
        i=0;
        System.out.println("~~恭喜以下参与者获得三等奖~~");
        while(i<prize3){
            System.out.println("参与者号码:"+iterator.next());
            iterator.remove();
            i++;
        }
        System.out.println("~~本次活动已结束，谢谢各位的参与~~");
    }
    
    public static void main(String[] args) {
        choujiang setLearning = new choujiang();
        setLearning.addToSte();
        setLearning.drawPrize();
    }
    
}

程序运行结果如下：