【Core Java】彩票选取中奖数字-数组例子

package im.zyf.javacore;

import java.util.Arrays;
import java.util.Scanner;

public class LotteryDrawing {

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        System.out.println("how many numbers do you need?");
        int k = in.nextInt();

        System.out.println("what is the highest number?");
        int h = in.nextInt();

        int[] harr = new int[h];
        for (int i = 0; i < h; i++) {
            harr[i] = i + 1;
        }

        int[] karr = new int[k];
        for (int i = 0; i < k; i++) {
            int random = (int) (Math.random() * h);
            karr[i] = harr[random];
            //将数组最后的值，代替掉被取走的值
            harr[random] = harr[h - 1];
            //数组长度减1
            h--;
        }
        Arrays.sort(karr);
        System.out.println(Arrays.toString(karr));
    }
}