Given a number and its permutation, how can we find out the number of transformations by which the number could be transformed into its permutation ? eg: 2315 and 5213 are given. 2315 can be transformed into 5213 in a series of 2 transformations.

#include<iostream.h>

#include<conio.h>

int a1[]={2,3,1,5};

int a2[]={5,2,1,3};

int counter,n=4;

void swap(int i,int j)

{

      counter++;

      cout<<"\nswap "<<a2[i]<<" and "<<a2n[j];

      int temp=a2[i];

      a2[i]=a2[j];

      a2[j]=temp;

}

void main()

{

      clrscr();

      for(int i=0;i<n;i++)

            if(a1[i]!=a2[i])

            {

                  int pos=0;

                  while(a2[pos]!=a1[i])

                        pos++;

                  swap(pos,i);

            }

      cout<<"\n\nno of operations required = "<<counter;

      getch();

}