Java第六次作业

import java.util.ArrayList;
import java.util.Collections;
import java.util.Random;
import java.util.*;
public class choujiang {
    private ArrayList<Integer> cards;

    public void deal(int num){
        if (cards==null){
            cards=new ArrayList<Integer>();
            for(num=1;num<=100;num++){
                cards.add(num);
            }
        }
        Collections.shuffle(cards);
    }
    public void draw(){
       Random ra=new Random();
        int s =ra.nextInt(cards.size());
        System.out.println("一等奖:"+ cards.get(s));
        cards.remove(cards.get(s));
        Collections.shuffle(cards);
        
        for(int i=0;i<2;i++){
            int stwo=ra.nextInt(cards.size());
            System.out.println("二等奖:"+ cards.get(stwo));
            cards.remove(cards.get(stwo));
            }
        Collections.shuffle(cards);
            for(int j =0;j<3;j++){
                int sthree =ra.nextInt(cards.size());
                System.out.println("三等奖:"+cards.get(sthree));
                cards.remove(cards.get(sthree));
            }

         }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        choujiang c = new choujiang();
        c.deal(0);
        c.draw();
    }
}