using System;

​

public class formPermut

{

   public void swapTwoNumber (ref int a, ref int b)

   {

      int temp = a;

      a = b;

      b = temp;

   }

   public void prnPermut (int []list, int k, int m)

   {

      int i;

      if (k == m)

      { 

         for (i = 0; i <= m; i++)

         Console.Write ("{0}",list [i]);

         Console.Write (" ");

      }

      else

         for (i = k; i <= m; i++)

         {

            swapTwoNumber (ref list [k], ref list [i]);

            prnPermut (list, k+1, m);

            swapTwoNumber (ref list [k], ref list [i]);

         }

   }

}

public class RecExercise11

{

   public static void Main()

   {

       int n,i;

      formPermut test = new formPermut();

      int[] arr1 = new int[5];

        Console.WriteLine("\n\n Recursion : Generate all possible permutations of an array :");

        Console.WriteLine("------------------------------------------------------------------");      

        Console.Write(" Input the number of elements to store in the array [maximum 5 digits ] :");

        n = Convert.ToInt32(Console.ReadLine());    

        Console.Write(" Input {0} number of elements in the array :\n",n);

        for(i=0;i<n;i++)

            {

            Console.Write(" element - {0} : ",i);

            arr1[i] = Convert.ToInt32(Console.ReadLine()); 

            }      

​

        Console.Write ("\n The Permutations with a combination of {0} digits are : \n",n);

        test.prnPermut(arr1, 0, n-1);

        Console.Write ("\n\n");

   }

}