74 lines
2.0 KiB
C
74 lines
2.0 KiB
C
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/*=============================================================================
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This file is part of FLINT.
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FLINT 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 of the License, or
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(at your option) any later version.
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FLINT 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 FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2010,2011 Fredrik Johansson
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******************************************************************************/
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#include <stdio.h>
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#include <stdlib.h>
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#include "flint.h"
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#include "ulong_extras.h"
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#include "nmod_vec.h"
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#include "nmod_mat.h"
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int
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nmod_mat_solve(nmod_mat_t X, const nmod_mat_t A, const nmod_mat_t B)
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{
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slong i, rank, *perm;
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nmod_mat_t LU;
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int result;
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if (A->r == 0 || B->c == 0)
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return 1;
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nmod_mat_init_set(LU, A);
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perm = flint_malloc(sizeof(slong) * A->r);
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for (i = 0; i < A->r; i++)
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perm[i] = i;
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rank = nmod_mat_lu(perm, LU, 1);
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if (rank == A->r)
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{
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nmod_mat_t PB;
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nmod_mat_window_init(PB, B, 0, 0, B->r, B->c);
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for (i = 0; i < A->r; i++)
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PB->rows[i] = B->rows[perm[i]];
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nmod_mat_solve_tril(X, LU, PB, 1);
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nmod_mat_solve_triu(X, LU, X, 0);
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nmod_mat_window_clear(PB);
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result = 1;
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}
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else
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{
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result = 0;
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}
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nmod_mat_clear(LU);
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flint_free(perm);
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return result;
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}
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