/*
 * This code is from "Algorithms in C, Third Edition,"
 * by Robert Sedgewick, Addison Wesley Longman, 1998.
 */
#include <stdlib.h>
#include "Item.h"
#include "ST.h"

typedef struct STnode* link;
struct STnode { Item item; link next; };
static link head, z;
static int N;
static link NEW(Item item, link next)      
  { link x = malloc(sizeof *x);
    x->item = item; x->next = next;     
    return x;                         
  }                                   
void STinit(int max) 
  { N = 0; head = (z = NEW(NULLitem, NULL)); }
int STcount() { return N; }
Item searchR(link t, Key v)
  { 
    if (t == z) return NULLitem;
    if (eq(key(t->item), v)) return t->item;
    return searchR(t->next, v);
  }
Item STsearch(Key v)
  { return searchR(head, v); }
void STinsert(Item item)
  { head = NEW(item, head); N++; }