1 /* $OpenBSD: warshall.c,v 1.8 2003/06/19 16:34:53 pvalchev Exp $ */ 2 /* $NetBSD: warshall.c,v 1.4 1996/03/19 03:21:51 jtc Exp $ */ 3 4 /* 5 * Copyright (c) 1989 The Regents of the University of California. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Robert Paul Corbett. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)warshall.c 5.4 (Berkeley) 5/24/93"; 39 #else 40 static char rcsid[] = "$OpenBSD: warshall.c,v 1.8 2003/06/19 16:34:53 pvalchev Exp $"; 41 #endif 42 #endif /* not lint */ 43 44 #include "defs.h" 45 46 void transitive_closure(unsigned int *, int); 47 48 void 49 transitive_closure(unsigned int *R, int n) 50 { 51 int rowsize; 52 unsigned i; 53 unsigned *rowj; 54 unsigned *rp; 55 unsigned *rend; 56 unsigned *ccol; 57 unsigned *relend; 58 unsigned *cword; 59 unsigned *rowi; 60 61 rowsize = WORDSIZE(n); 62 relend = R + n*rowsize; 63 64 cword = R; 65 i = 0; 66 rowi = R; 67 while (rowi < relend) 68 { 69 ccol = cword; 70 rowj = R; 71 72 while (rowj < relend) 73 { 74 if (*ccol & (1 << i)) 75 { 76 rp = rowi; 77 rend = rowj + rowsize; 78 while (rowj < rend) 79 *rowj++ |= *rp++; 80 } 81 else 82 { 83 rowj += rowsize; 84 } 85 86 ccol += rowsize; 87 } 88 89 if (++i >= BITS_PER_WORD) 90 { 91 i = 0; 92 cword++; 93 } 94 95 rowi += rowsize; 96 } 97 } 98 99 void 100 reflexive_transitive_closure(unsigned int *R, int n) 101 { 102 int rowsize; 103 unsigned i; 104 unsigned *rp; 105 unsigned *relend; 106 107 transitive_closure(R, n); 108 109 rowsize = WORDSIZE(n); 110 relend = R + n*rowsize; 111 112 i = 0; 113 rp = R; 114 while (rp < relend) 115 { 116 *rp |= (1 << i); 117 if (++i >= BITS_PER_WORD) 118 { 119 i = 0; 120 rp++; 121 } 122 123 rp += rowsize; 124 } 125 } 126