package choujiang; import java.util.ArrayList; import java.util.Collections; import java.util.Random; public class Draw { private ArrayList<Integer>list; public Draw(){ list=new ArrayList<Integer>(); } public void deal(int num){ //向容器中添加奖券(使用循环) for (int i=1;i<num;i++){ list.add(i); } //打乱顺序 Collections.shuffle(list); } public void drawLottery(int n){ //产生n个指定范围(0-lise.size)的随机数 Random l = new Random(); /* * 获得容器中以产生的随机数为下标的元素的内容 * 即为获奖的奖券的抽奖号,输出 */ for(int j=1;j<n;j++){ int index = l.nextInt(list.size()); System.out.println(list.get(index)+" "); list.remove(index); } //将已获奖的元素(奖券)从容器中删除 System.out.println(); } public static void main(String[] args) { // TODO Auto-generated method stub Draw a = new Draw(); a.deal(2000); System.out.println(".....一等奖....."); a.drawLottery(3); System.out.println(".....二等奖....."); a.drawLottery(10); System.out.println(".....三等奖....."); a.drawLottery(15); }
}