LotteryDrawing.java

import java.util.*;

public class LotteryDrawing
{
  public static void main(String args[])
    {
    Scanner in = new Scanner(System.in);
    
    System.out.print("How many numbers draw?");
    int k = in.nextInt();
    
    System.out.print("What is highest number?");
    int n = in.nextInt();
    // 배열을 1, 2, 3 .... n 으로 채워라
    int[] numbers = new int[n];
    for (int i = 0; i<numbers.length; i++)
      numbers[i] = i + 1;
    
    int[] result = new int[k];
    
    for (int i = 0;i < result.length; i++)
    {
      // 0부터 n-1까지 랜덤 인덱스 만들어라
      int r = (int)(Math.random()*n);
      
      // pick the elemnet at the random location and copy
      result[i] = numbers[r];
      
      // move last elemnet into random location for uniqueness
      numbers[r] = numbers[n-1];
      n--; // reduse the size because of uniqueness
    }
    
    Arrays.sort(result);
    System.out.println("Bet as follow. It'll make you rich!");
      for(int r : result)
        System.out.println(r);
  }
} end of lottery drawn class

 

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