/*
 * This code is from "Algorithms in C, Third Edition,"
 * by Robert Sedgewick, Addison Wesley Longman, 1998.
 */
Item searchR(link t, Key v, int k)
  { 
    if (eq(v, key(t->item))) return t->item;
    if (less(v, key(t->next[k]->item))) 
      { 
        if (k == 0) return NULLitem;
        return searchR(t, v, k-1); 
      }
    return searchR(t->next[k], v, k);
  }
Item STsearch(Key v)
  { return searchR(head, v, lgN); }