JAVA第六次作业 抽奖

import java.util.ArrayList;
import java.util.Collections;
import java.util.Random;

public class choujiang {
private ArrayList list;

public void deal(){
	//向list容器中添加指定数量num的整数
	
	if (list == null){
		list = new ArrayList<Integer>();
		for(int i=1;i<=100;i++){
			list.add(i);
			
		}
	}
	
	//打乱list中的元素的顺序
	Collections.shuffle(list);
}
//抽奖的方法:指出指定数量S的奖项
public void draw(){
	Random rd = new Random(); 
	int index1 =rd.nextInt(list.size());
	System.out.println("获得一等奖的号码是:"+list.get(index1));
	list.remove(index1);
	Collections.shuffle(list);
	int index2 =rd.nextInt(list.size());
	System.out.println("获得二等奖的号码是:"+list.get(index2));
	list.remove(index2);
	Collections.shuffle(list);
	int index3 =rd.nextInt(list.size());
	System.out.println("获得三等奖的号码是:"+list.get(index3));
	
	
}

public static void main(String[] args) {
	// TODO Auto-generated method stub
	choujiang cj = new choujiang();
	cj.deal();
	cj.draw();

}

}

原文地址:https://www.cnblogs.com/www123/p/5486127.html