/* Returns the smallest |i| such that |array[i] == key|,
   or |-1| if |key| is not in |array[]|.
   |array[]| must be an array of |n int|s,
   sorted in ascending order,
   with room for an |(n + 1)|th element to set to |INT_MAX|. */
int
seq_sorted_sentinel_search_2 (int array[], int n, int key)
{
  int *p;

  array[n] = INT_MAX;
  for (p = array; *p < key; p++)
    /* Nothing to do. */;
  return p - array < n && *p == key ? p - array : -1;
}