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priorityq-heap.h
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1/*
2 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice including the dates of first publication and
13 * either this permission notice or a reference to
14 * http://oss.sgi.com/projects/FreeB/
15 * shall be included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
21 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
22 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 *
25 * Except as contained in this notice, the name of Silicon Graphics, Inc.
26 * shall not be used in advertising or otherwise to promote the sale, use or
27 * other dealings in this Software without prior written authorization from
28 * Silicon Graphics, Inc.
29 */
30/*
31** Author: Eric Veach, July 1994.
32**
33*/
34
35#ifndef __priorityq_heap_h_
36#define __priorityq_heap_h_
37
38/* Use #define's so that another heap implementation can use this one */
39
40#define PQkey PQHeapKey
41#define PQhandle PQHeapHandle
42#define PriorityQ PriorityQHeap
43
44#define pqNewPriorityQ(leq) __gl_pqHeapNewPriorityQ(leq)
45#define pqDeletePriorityQ(pq) __gl_pqHeapDeletePriorityQ(pq)
46
47/* The basic operations are insertion of a new key (pqInsert),
48 * and examination/extraction of a key whose value is minimum
49 * (pqMinimum/pqExtractMin). Deletion is also allowed (pqDelete);
50 * for this purpose pqInsert returns a "handle" which is supplied
51 * as the argument.
52 *
53 * An initial heap may be created efficiently by calling pqInsert
54 * repeatedly, then calling pqInit. In any case pqInit must be called
55 * before any operations other than pqInsert are used.
56 *
57 * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
58 * This may also be tested with pqIsEmpty.
59 */
60#define pqInit(pq) __gl_pqHeapInit(pq)
61#define pqInsert(pq,key) __gl_pqHeapInsert(pq,key)
62#define pqMinimum(pq) __gl_pqHeapMinimum(pq)
63#define pqExtractMin(pq) __gl_pqHeapExtractMin(pq)
64#define pqDelete(pq,handle) __gl_pqHeapDelete(pq,handle)
65#define pqIsEmpty(pq) __gl_pqHeapIsEmpty(pq)
66
67
68/* Since we support deletion the data structure is a little more
69 * complicated than an ordinary heap. "nodes" is the heap itself;
70 * active nodes are stored in the range 1..pq->size. When the
71 * heap exceeds its allocated size (pq->max), its size doubles.
72 * The children of node i are nodes 2i and 2i+1.
73 *
74 * Each node stores an index into an array "handles". Each handle
75 * stores a key, plus a pointer back to the node which currently
76 * represents that key (ie. nodes[handles[i].node].handle == i).
77 */
78
79typedef void *PQkey;
80typedef long PQhandle;
81typedef struct PriorityQ PriorityQ;
82
83typedef struct { PQhandle handle; } PQnode;
84typedef struct { PQkey key; PQhandle node; } PQhandleElem;
85
86struct PriorityQ {
89 long size, max;
92 int (*leq)(PQkey key1, PQkey key2);
93};
94
95PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) );
97
98void pqInit( PriorityQ *pq );
101void pqDelete( PriorityQ *pq, PQhandle handle );
102
103
104#define __gl_pqHeapMinimum(pq) ((pq)->handles[(pq)->nodes[1].handle].key)
105#define __gl_pqHeapIsEmpty(pq) ((pq)->size == 0)
106
107#endif
#define pqNewPriorityQ(leq)
#define pqDeletePriorityQ(pq)
#define pqInit(pq)
long PQhandle
#define pqDelete(pq, handle)
void * PQkey
#define pqExtractMin(pq)
#define PQhandle
#define PQkey
#define pqInsert(pq, key)
PQHeapKey PQkey
Definition priorityq.h:93
PQHeapHandle PQhandle
Definition priorityq.h:94
PQhandle handle
PQnode * nodes
PQhandleElem * handles
PQhandle freeList