Thread: LAST issue! Random permutation array!

I have the array printing out just 0's. I am not sure what i have to input to make it output random digits. I want random digits 0-9, I am not sure what to do. This is the last program i need help on. Thank you for any help!

/**
   This class prints 5 permutations of the numbers 1 through 10.
*/
public class PermutationPrinter
{  
   public static void main(String[] args)
   {  
      PermutationGenerator gen = new PermutationGenerator(10);      
 
      for (int i = 1; i <= 5; i++)
      {  
         for (int n : gen.nextPermutation())
            System.out.print(" " +  n);
            }
   }
}

import java.util.Random;
import java.util.*;
/**
   This class generates permutations of a sequence of integers 
   1...length.
*/
public class PermutationGenerator
{   
  ArrayList<Integer> number = new ArrayList<Integer>();
  int size; 
 
   /**
      Construct a PermutationGenerator object.
      @param length the length of the permutations generated
      by this generator.
   */
   public PermutationGenerator(int length)
   {	size = length;
   for (int i = 0; i <= length; i++){
   number.add(i);
   } 
   }
   /**
      Gets the next permutation.
      @return the array containing the next permutation
   */
   public int[] nextPermutation()
   { 
      int[] x = new int[size];
	  for( int i = 0; i<size; i++){
		Random k = new Random();
		int y = k.nextInt(number.size());
 
	  }
	  return x;
	}
}

In your nextPermutation() method, you are never adding the values from the for loop to your int array. So you are just creating a new array and passing on that empty array, which would contain all 0s

That makes sense actually, but how would i go about doing that?

Originally Posted by bankoscarpa

That makes sense actually, but how would i go about doing that?

You can just make an assignment statement after the creation of the random number (y). You should assign y to an index of your array.

Something like

x[i] = y;