_OPTIMAL DETERMINATION OF OBJECT EXTENTS_
by by Victor J. Duvanenko, W.E. Robbins, and Ronald S. Gyurcsik


[LISTINĒ ONE]

/* min.c -- Procedure to find the smallest element of the array.
   The number of elements in the array must be > 0.  ( n > 0 ) */
float find_min( array, n )
float array[];        /* input array */
int n;                /* number of elements in the array ( n > 0 ) */
{
  register i;  float min;

  min = array[0];
  for( i = 1; i < n; i++ )
     if ( min > array[i] )   min = array[i];
  return( min );
}
/* Procedure to find the largest element of the array.
   The number of elements in the array must be > 0.  ( n > 0 ) */
float find_max( array, n )
float array[];        /* input array */
int n;                /* number of elements in the array ( n > 0 ) */
{
  register i;  float max;

  max = array[0];
  for( i = 1; i < n; i++ )
     if ( max < array[i] )   max = array[i];
  return( max );
}


[LISTING TWO]

/* min_max.c  -- Procedure to find the smallest and the largest element of 
   the array. The number of elements in the array must be > 0.  ( n > 0 ) */
void find_min_max( array, n, min, max )
float array[];        /* input array */
int n;                /* number of elements in the array ( n > 0 ) */
float *min, *max;     /* pointers to the return values */
{
  register i;

  if ( n <= 1 )
     *min = *max = array[0];
  else {
     if ( array[0] > array[1] ) {    /* establish the basis min and max */
        *max = array[0];
        *min = array[1];
     }
     else {
        *max = array[1];
        *min = array[0];
     }
     for( i = 2; ( i + 2 ) <= n; i += 2 )
        if ( array[ i ] > array[ i + 1 ] ) {
           if ( array[ i     ] > *max )   *max = array[ i ];
           if ( array[ i + 1 ] < *min )   *min = array[ i + 1 ];
        }
        else {
           if ( array[ i + 1 ] > *max )   *max = array[ i + 1 ];
           if ( array[ i     ] < *min )   *min = array[ i ];
        }
     if ( i < n )        /* handle the odd/last array element */
       if ( *max < array[i] )  *max = array[i];
       else if ( *min > array[i] )  *min = array[i];
  }
}