【每日日报】第十九天

1 今天继续看了第三章 还写了第三章的题

2 一些关于数组的工具函数

package Array;
import java.util.Arrays;
public class ArraySort {
 public static void main(String[] args){
  int[] ary = {2,3,4,5,9,7,8};
  Arrays.sort(ary);      //排序
  System.out.println(Arrays.toString(ary));   //打印数组
  int index = Arrays.binarySearch(ary, 3);  //二分法
  System.out.println(index);
 }
}

 关于产生随机数的函数：

package Array;
import java.util.Random;
public class RandomDome {
    public static void main(String[] args){
        Random ran = new Random();
        int a = ran.nextInt(10000);//随机生成0~10000之间的整数
        System.out.println(a);
    }
}

双色球：

package Array;
import java.util.Arrays;
import java.util.Random;

public class DoubleColor {
    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 ));
        
        }
    }