125 lines
3 KiB
C
125 lines
3 KiB
C
/* $NetBSD: warshall.c,v 1.8 2006/05/24 18:01:43 christos Exp $ */
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/*
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* Copyright (c) 1989 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Robert Paul Corbett.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#if defined(__RCSID) && !defined(lint)
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#if 0
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static char sccsid[] = "@(#)warshall.c 5.4 (Berkeley) 5/24/93";
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#else
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__RCSID("$NetBSD: warshall.c,v 1.8 2006/05/24 18:01:43 christos Exp $");
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#endif
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#endif /* not lint */
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#include "defs.h"
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static void transitive_closure(unsigned *, int);
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static void
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transitive_closure(unsigned *R, int n)
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{
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int rowsize;
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unsigned i;
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unsigned *rowj;
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unsigned *rp;
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unsigned *rend;
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unsigned *ccol;
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unsigned *relend;
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unsigned *cword;
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unsigned *rowi;
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rowsize = WORDSIZE(n);
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relend = R + n*rowsize;
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cword = R;
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i = 0;
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rowi = R;
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while (rowi < relend)
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{
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ccol = cword;
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rowj = R;
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while (rowj < relend)
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{
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if (*ccol & (1 << i))
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{
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rp = rowi;
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rend = rowj + rowsize;
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while (rowj < rend)
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*rowj++ |= *rp++;
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}
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else
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{
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rowj += rowsize;
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}
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ccol += rowsize;
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}
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if (++i >= BITS_PER_WORD)
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{
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i = 0;
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cword++;
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}
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rowi += rowsize;
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}
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}
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void
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reflexive_transitive_closure(unsigned *R, int n)
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{
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int rowsize;
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unsigned i;
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unsigned *rp;
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unsigned *relend;
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transitive_closure(R, n);
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rowsize = WORDSIZE(n);
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relend = R + n*rowsize;
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i = 0;
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rp = R;
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while (rp < relend)
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{
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*rp |= (1 << i);
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if (++i >= BITS_PER_WORD)
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{
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i = 0;
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rp++;
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}
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rp += rowsize;
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}
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}
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