#include "is-permutation.h"

int
is_permutation (int a1[], int a2[], int size)
{
  int i;
  for (i = 0; i < size; i++)
    {
      if (index_of (a1, size, a2[i]) == -1)
        return 0;
      if (index_of (a2, size, a1[i]) == -1)
        return 0;
    } // for
  return 1;
} // is_permutation

/**
 * Procedure:
 *   index_of
 * Parameters:
 *   a, an array of integers
 *   limit, an integer
 *   value, an integer
 * Purpose:
 *   Finds an index of i in a.
 * Produces:
 *   index, an integer
 * Preconditions:
 *   0 <= limit <= length(a)
 * Postconditions:
 *   a has not been modified
 *   If there exists a j in [0..limit) s.t. a[j] == value, then
 *     index >= 0 and a[index] == value
 *   If no such j exists, then
 *     index == -1
 */
int
index_of (int a[], int limit, int value)
{
  int i;
  for (i = 0; i < limit; i++)
    if (a[i] == value)
      return i;
  return -1;
} // index_of