2020.7.12

一、今日学习内容

    1、第三章综合实例：双色球

import java.util.Random;
import java.util.Arrays;
public class Ball {
    public static void main(String[] args) {
        String[] pool= {"01","02","03","04","05","06","07","08","09","10","11","12",
                "13","14","15","16","17","18","19","20","21","22","23","24","25","26",
                "27","28","29","30","31","32","33"};
        boolean[] used=new boolean[pool.length];
        String[] balls=new String[6];
        Random random=new Random();
        int i;
        int index=0;
        while(true)
        {
            i=random.nextInt(pool.length);
            if(used[i]) {
                continue;
            }
            balls[index++]=pool[i];
            used[i]=true;
            if(index==balls.length) break;
        }
        Arrays.sort(balls);
        String[] newballs=new String[7];
        for(int m=0;m<balls.length;m++) {
            newballs[m]=balls[m];
        }
        newballs[newballs.length-1]=pool[random.nextInt(16)];
        System.out.println("双色球："+Arrays.toString(newballs));
    }

}

     输出结果：双色球：[01, 13, 16, 25, 29, 33, 14]

二、遇到的问题

     有的问题想不到思路，不能有效运用学到的知识

三、明日计划

    学习第四章内容：类