#define lo 12
#define hi 20
#define Nitems 9 /* (hi-lo+1) */

typedef Item *Collection[Nitems];

Item *search(Collection c, Key k)
{
	int ix = indexOf(k);
	return c[ix];
}

int indexOf(Key k)
{
	assert(lo <= k && k <= hi);
	return k-lo;
}