/*
 * This code is from "Algorithms in C, Third Edition,"
 * by Robert Sedgewick, Addison Wesley Longman, 1998.
 */
int count(link h)
  { 
    if (h == NULL) return 0;
    return count(h->l) + count(h->r) + 1;
  }
int height(link h)
  { int u, v;
    if (h == NULL) return -1;
    u = height(h->l); v = height(h->r);
    if (u > v) return u+1; else return v+1;
  }