C37 Answer

/* Puzzle C37 -- shift every array element N positions right; */
/*               the first N elements get 0 */

void shiftRightNArray( int arr[], int size, int shift )
{
  int j;
      
  /* If the shift amount is zero or negative, do nothing */
  if ( shift<=0 ) return;
  
  /* If the shift amount is more than the number of elements, */
  /* zero the array */
  if ( shift>=size )
  {
    for ( j=0; j<size; j++ )
      arr[j] = 0;
    return;
  }

  /* Copy elements into their new locations */
  for ( j=size-1; j>=shift; j-- )
    arr[j] = arr[j-shift];
    
  /* Zero the first N slots */
  for ( j=0; j<shift; j++ )
    arr[j] = 0;      
}