LotteryDrawing

import java.util.*;

public class MyTest{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);

        System.out.print("How many numbers do you need to draw? ");
        int k = in.nextInt();

        System.out.print("What is the highest number you can draw? ");
        int n = in.nextInt();

        //fill an array with numbers 1 2 3... n
        int[] numbers = new int[n];
        for(int i = 0; i < numbers.length; i ++)
            numbers[i] = i + 1;

        //draw k numbers and put them into a second array
        int[] result = new int[k];
        for(int i = 0; i < result.length; i ++){
            // make a random index between 0 and n - 1
            int r = (int)(Math.random() * n);

            //pick the element at the random location
            result[i] = numbers[r];

            //move the last element into the random location\
            //ps: I guess the author must consider the Poker when he write down these codes ..........
            numbers[r] = numbers[n - 1];
            n --;
        }

        //print the sorted array
        Arrays.sort(result);
        System.out.print("Bet the following combination. It's make you rich！");
        for(int r: result)
            System.out.println(r);
    }
}