Input :

  A[4] = {0,4,-1,1000} - Actual Array
  P[4] = {1,0,3,2} - Order to be reshuffled 

Output:

    A[4] = {4,0,1000,-1}

Condition : Don't use an additional array as memory. Can use an extra variable or two.

Problem : I have the below program in C++, but this fails for certain inputs of array P.

#include<iostream>

using namespace std;

void swap(int *a_r,int *r)
{
    int temp = *r;
    *r = *a_r;
    *a_r = temp;
}
int main()
{
    int A[4] = {0,4,-1,1000};
    int P[4] = {3,0,1,2};
    int value = A[0] , dest = P[0];

    for(int i=0; i<4;i++)
    {
        swap(&A[dest],&value);
        dest = P[dest];
    }
    for(int i=0;i<4;i++)
        cout<<A[i]<<" ";
}