93 lines
3.2 KiB
C
93 lines
3.2 KiB
C
#ifndef __priorityq_heap_h_
|
|
#define __priorityq_heap_h_
|
|
|
|
/*
|
|
** Copyright 1994, Silicon Graphics, Inc.
|
|
** All Rights Reserved.
|
|
**
|
|
** This is UNPUBLISHED PROPRIETARY SOURCE CODE of Silicon Graphics, Inc.;
|
|
** the contents of this file may not be disclosed to third parties, copied or
|
|
** duplicated in any form, in whole or in part, without the prior written
|
|
** permission of Silicon Graphics, Inc.
|
|
**
|
|
** RESTRICTED RIGHTS LEGEND:
|
|
** Use, duplication or disclosure by the Government is subject to restrictions
|
|
** as set forth in subdivision (c)(1)(ii) of the Rights in Technical Data
|
|
** and Computer Software clause at DFARS 252.227-7013, and/or in similar or
|
|
** successor clauses in the FAR, DOD or NASA FAR Supplement. Unpublished -
|
|
** rights reserved under the Copyright Laws of the United States.
|
|
**
|
|
** Author: Eric Veach, July 1994.
|
|
*/
|
|
|
|
/* Use #define's so that another heap implementation can use this one */
|
|
|
|
#define PQkey PQHeapKey
|
|
#define PQhandle PQHeapHandle
|
|
#define PriorityQ PriorityQHeap
|
|
|
|
#define pqNewPriorityQ(leq) __gl_pqHeapNewPriorityQ(leq)
|
|
#define pqDeletePriorityQ(pq) __gl_pqHeapDeletePriorityQ(pq)
|
|
|
|
/* The basic operations are insertion of a new key (pqInsert),
|
|
* and examination/extraction of a key whose value is minimum
|
|
* (pqMinimum/pqExtractMin). Deletion is also allowed (pqDelete);
|
|
* for this purpose pqInsert returns a "handle" which is supplied
|
|
* as the argument.
|
|
*
|
|
* An initial heap may be created efficiently by calling pqInsert
|
|
* repeatedly, then calling pqInit. In any case pqInit must be called
|
|
* before any operations other than pqInsert are used.
|
|
*
|
|
* If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
|
|
* This may also be tested with pqIsEmpty.
|
|
*/
|
|
#define pqInit(pq) __gl_pqHeapInit(pq)
|
|
#define pqInsert(pq,key) __gl_pqHeapInsert(pq,key)
|
|
#define pqMinimum(pq) __gl_pqHeapMinimum(pq)
|
|
#define pqExtractMin(pq) __gl_pqHeapExtractMin(pq)
|
|
#define pqDelete(pq,handle) __gl_pqHeapDelete(pq,handle)
|
|
#define pqIsEmpty(pq) __gl_pqHeapIsEmpty(pq)
|
|
|
|
|
|
/* Since we support deletion the data structure is a little more
|
|
* complicated than an ordinary heap. "nodes" is the heap itself;
|
|
* active nodes are stored in the range 1..pq->size. When the
|
|
* heap exceeds its allocated size (pq->max), its size doubles.
|
|
* The children of node i are nodes 2i and 2i+1.
|
|
*
|
|
* Each node stores an index into an array "handles". Each handle
|
|
* stores a key, plus a pointer back to the node which currently
|
|
* represents that key (ie. nodes[handles[i].node].handle == i).
|
|
*/
|
|
|
|
typedef void *PQkey;
|
|
typedef long PQhandle;
|
|
typedef struct PriorityQ PriorityQ;
|
|
|
|
typedef struct { PQhandle handle; } PQnode;
|
|
typedef struct { PQkey key; PQhandle node; } PQhandleElem;
|
|
|
|
struct PriorityQ {
|
|
PQnode *nodes;
|
|
PQhandleElem *handles;
|
|
long size, max;
|
|
PQhandle freeList;
|
|
int initialized;
|
|
int (*leq)(PQkey key1, PQkey key2);
|
|
};
|
|
|
|
PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) );
|
|
void pqDeletePriorityQ( PriorityQ *pq );
|
|
|
|
void pqInit( PriorityQ *pq );
|
|
PQhandle pqInsert( PriorityQ *pq, PQkey key );
|
|
PQkey pqExtractMin( PriorityQ *pq );
|
|
void pqDelete( PriorityQ *pq, PQhandle handle );
|
|
|
|
|
|
#define __gl_pqHeapMinimum(pq) ((pq)->handles[(pq)->nodes[1].handle].key)
|
|
#define __gl_pqHeapIsEmpty(pq) ((pq)->size == 0)
|
|
|
|
#endif
|