ocaml/yacc/warshall.c

98 lines
2.5 KiB
C

/**************************************************************************/
/* */
/* OCaml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. */
/* */
/* All rights reserved. This file is distributed under the terms of */
/* the GNU Lesser General Public License version 2.1, with the */
/* special exception on linking described in the file LICENSE. */
/* */
/**************************************************************************/
/* Based on public-domain code from Berkeley Yacc */
#include "defs.h"
void transitive_closure(unsigned int *R, int n)
{
register int rowsize;
register unsigned mask;
register unsigned *rowj;
register unsigned *rp;
register unsigned *rend;
register unsigned *ccol;
register unsigned *relend;
register unsigned *cword;
register unsigned *rowi;
rowsize = WORDSIZE(n);
relend = R + n*rowsize;
cword = R;
mask = 1;
rowi = R;
while (rowi < relend)
{
ccol = cword;
rowj = R;
while (rowj < relend)
{
if (*ccol & mask)
{
rp = rowi;
rend = rowj + rowsize;
while (rowj < rend)
*rowj++ |= *rp++;
}
else
{
rowj += rowsize;
}
ccol += rowsize;
}
mask <<= 1;
if (mask == 0)
{
mask = 1;
cword++;
}
rowi += rowsize;
}
}
void reflexive_transitive_closure(unsigned int *R, int n)
{
register int rowsize;
register unsigned mask;
register unsigned *rp;
register unsigned *relend;
transitive_closure(R, n);
rowsize = WORDSIZE(n);
relend = R + n*rowsize;
mask = 1;
rp = R;
while (rp < relend)
{
*rp |= mask;
mask <<= 1;
if (mask == 0)
{
mask = 1;
rp++;
}
rp += rowsize;
}
}