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

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

