C32 Answer

/* Puzzle C32 -- reverse the elements in an array between
   index Low and High */

void reverseArrayRange( int arr[], int size, int low, int high )
{
  int j;
  int temp;
  int length;
  
  /* Adjust out-of-bounds indexes */
  if ( low < 0 ) low = 0;
  if ( high >= size ) high = size-1;
  
  length = high-low+1;
  
  for ( j=0; j < length/2; j++ )
  {
    temp = arr[low+j];
    arr[low+j] = arr[high-j];
    arr[high-j] = temp;
  }
}