#include <assert.h>
#include <stdlib.h>

int copyArray(int * a, int * cp, int len) {
  if (!a || !cp) return -1;
  int i;
  for (i = 0; i < len; i++)
    cp[i] = a[i];
  return 0;
}

// a unit test of copyArray
#define N 5
int main() {
  int a[N], b[N];
  int i;
  // initialize the source array
  for (i = 0; i < N; i++) a[i] = i;
  // should copy a's elements to b
  copyArray(a, b, N);
  // check that the copy indeed occurred
  for (i = 0; i < N; i++) 
    assert (a[i] == b[i]);
  // check corner cases
  assert (copyArray(NULL, a, 0));
  assert (copyArray(a, NULL, 0));
  return 0;
}