/**
  * Copyright (c): Uwe Schmidt, FH Wedel
  *
  * You may study, modify and distribute this source code
  * FOR NON-COMMERCIAL PURPOSES ONLY.
  * This copyright message has to remain unchanged.
  *
  * Note that this document is provided 'as is',
  * WITHOUT WARRANTY of any kind either expressed or implied.
  */

#ifndef HEAP_H__
#define HEAP_H__

/* usage:
   the type "Element" for the elements
   to be stored must be declared elsewere
   this type must support a compare function
   like strcmp, with results -1,0,+1
   reflecting the ordering relation

   see "Element.h" and "Element.c" examples
*/

typedef struct Node *Heap;

struct Node
{
  Element info;
  Heap l;
  Heap r;
};

extern Heap mkEmptyHeap(void);
extern Heap mkOneElemHeap(Element e);

extern int isEmptyHeap(Heap h);
extern Element minElem(Heap h);

extern Heap deleteMinElem(Heap h);
extern Heap insertElem(Element e, Heap h);
extern Heap mergeHeaps(Heap h1, Heap h2);

extern int invHeap(Heap h1);

#endif