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62 lines
1.9 KiB
C
62 lines
1.9 KiB
C
/* Generate transitive closure of a matrix,
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Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
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This file is part of Bison, the GNU Compiler Compiler.
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Bison is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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Bison is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Bison; see the file COPYING. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "system.h"
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#include "warshall.h"
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/*-------------------------------------------------------------.
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| Given n by n matrix of bits R, modify its contents to be the |
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| transive closure of what was given. |
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`-------------------------------------------------------------*/
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#define R(Num) (unsigned *) ((char *) R + ((Num) * rowsize))
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static void
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TC (unsigned *R, int n)
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{
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int rowsize = WORDSIZE (n) * sizeof (unsigned);
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int i, j, k;
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for (i = 0; i < n; ++i)
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for (j = 0; j < n; ++j)
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if (BITISSET (R (i), j))
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for (k = 0; k < rowsize; ++k)
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if (BITISSET (R (i), k))
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SETBIT (R (j), k);
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}
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/*---------------------------------------------------------------.
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| Reflexive Transitive Closure. Same as TC and then set all the |
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| bits on the diagonal of R. |
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`---------------------------------------------------------------*/
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void
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RTC (unsigned *R, int n)
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{
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int rowsize = WORDSIZE (n) * sizeof (unsigned);
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int i;
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TC (R, n);
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for (i = 0; i < n; ++i)
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SETBIT (R (i), i);
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}
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