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_sort_h_ 36 #define __priorityq_sort_h_ 37 38 #include "priorityq-heap.h" 39 40 #undef PQkey 41 #undef PQhandle 42 #undef PriorityQ 43 #undef pqNewPriorityQ 44 #undef pqDeletePriorityQ 45 #undef pqInit 46 #undef pqInsert 47 #undef pqMinimum 48 #undef pqExtractMin 49 #undef pqDelete 50 #undef pqIsEmpty 51 52 /* Use #define's so that another heap implementation can use this one */ 53 54 #define PQkey PQSortKey 55 #define PQhandle PQSortHandle 56 #define PriorityQ PriorityQSort 57 58 #define pqNewPriorityQ(leq) __gl_pqSortNewPriorityQ(leq) 59 #define pqDeletePriorityQ(pq) __gl_pqSortDeletePriorityQ(pq) 60 61 /* The basic operations are insertion of a new key (pqInsert), 62 * and examination/extraction of a key whose value is minimum 63 * (pqMinimum/pqExtractMin). Deletion is also allowed (pqDelete); 64 * for this purpose pqInsert returns a "handle" which is supplied 65 * as the argument. 66 * 67 * An initial heap may be created efficiently by calling pqInsert 68 * repeatedly, then calling pqInit. In any case pqInit must be called 69 * before any operations other than pqInsert are used. 70 * 71 * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key. 72 * This may also be tested with pqIsEmpty. 73 */ 74 #define pqInit(pq) __gl_pqSortInit(pq) 75 #define pqInsert(pq,key) __gl_pqSortInsert(pq,key) 76 #define pqMinimum(pq) __gl_pqSortMinimum(pq) 77 #define pqExtractMin(pq) __gl_pqSortExtractMin(pq) 78 #define pqDelete(pq,handle) __gl_pqSortDelete(pq,handle) 79 #define pqIsEmpty(pq) __gl_pqSortIsEmpty(pq) 80 81 82 /* Since we support deletion the data structure is a little more 83 * complicated than an ordinary heap. "nodes" is the heap itself; 84 * active nodes are stored in the range 1..pq->size. When the 85 * heap exceeds its allocated size (pq->max), its size doubles. 86 * The children of node i are nodes 2i and 2i+1. 87 * 88 * Each node stores an index into an array "handles". Each handle 89 * stores a key, plus a pointer back to the node which currently 90 * represents that key (ie. nodes[handles[i].node].handle == i). 91 */ 92 93 typedef PQHeapKey PQkey; 94 typedef PQHeapHandle PQhandle; 95 typedef struct PriorityQ PriorityQ; 96 97 struct PriorityQ { 98 PriorityQHeap *heap; 99 PQkey *keys; 100 PQkey **order; 101 PQhandle size, max; 102 int initialized; 103 int (*leq)(PQkey key1, PQkey key2); 104 }; 105 106 PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) ); 107 void pqDeletePriorityQ( PriorityQ *pq ); 108 109 int pqInit( PriorityQ *pq ); 110 PQhandle pqInsert( PriorityQ *pq, PQkey key ); 111 PQkey pqExtractMin( PriorityQ *pq ); 112 void pqDelete( PriorityQ *pq, PQhandle handle ); 113 114 PQkey pqMinimum( PriorityQ *pq ); 115 int pqIsEmpty( PriorityQ *pq ); 116 117 #endif 118