diff options
Diffstat (limited to 'test/monniaux/glpk-4.65/src/api/wcliqex.c')
| -rw-r--r-- | test/monniaux/glpk-4.65/src/api/wcliqex.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/test/monniaux/glpk-4.65/src/api/wcliqex.c b/test/monniaux/glpk-4.65/src/api/wcliqex.c new file mode 100644 index 00000000..53c2d521 --- /dev/null +++ b/test/monniaux/glpk-4.65/src/api/wcliqex.c @@ -0,0 +1,122 @@ +/* wcliqex.c (find maximum weight clique with exact algorithm) */ + +/*********************************************************************** +* This code is part of GLPK (GNU Linear Programming Kit). +* +* Copyright (C) 2009-2016 Andrew Makhorin, Department for Applied +* Informatics, Moscow Aviation Institute, Moscow, Russia. All rights +* reserved. E-mail: <mao@gnu.org>. +* +* GLPK is free software: you can redistribute it and/or modify it +* under the terms of the GNU General Public License as published by +* the Free Software Foundation, either version 3 of the License, or +* (at your option) any later version. +* +* GLPK is distributed in the hope that it will be useful, but WITHOUT +* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public +* License for more details. +* +* You should have received a copy of the GNU General Public License +* along with GLPK. If not, see <http://www.gnu.org/licenses/>. +***********************************************************************/ + +#include "env.h" +#include "glpk.h" +#include "wclique.h" + +static void set_edge(int nv, unsigned char a[], int i, int j) +{ int k; + xassert(1 <= j && j < i && i <= nv); + k = ((i - 1) * (i - 2)) / 2 + (j - 1); + a[k / CHAR_BIT] |= + (unsigned char)(1 << ((CHAR_BIT - 1) - k % CHAR_BIT)); + return; +} + +int glp_wclique_exact(glp_graph *G, int v_wgt, double *sol, int v_set) +{ /* find maximum weight clique with exact algorithm */ + glp_arc *e; + int i, j, k, len, x, *w, *ind, ret = 0; + unsigned char *a; + double s, t; + if (v_wgt >= 0 && v_wgt > G->v_size - (int)sizeof(double)) + xerror("glp_wclique_exact: v_wgt = %d; invalid parameter\n", + v_wgt); + if (v_set >= 0 && v_set > G->v_size - (int)sizeof(int)) + xerror("glp_wclique_exact: v_set = %d; invalid parameter\n", + v_set); + if (G->nv == 0) + { /* empty graph has only empty clique */ + if (sol != NULL) *sol = 0.0; + return 0; + } + /* allocate working arrays */ + w = xcalloc(1+G->nv, sizeof(int)); + ind = xcalloc(1+G->nv, sizeof(int)); + len = G->nv; /* # vertices */ + len = len * (len - 1) / 2; /* # entries in lower triangle */ + len = (len + (CHAR_BIT - 1)) / CHAR_BIT; /* # bytes needed */ + a = xcalloc(len, sizeof(char)); + memset(a, 0, len * sizeof(char)); + /* determine vertex weights */ + s = 0.0; + for (i = 1; i <= G->nv; i++) + { if (v_wgt >= 0) + { memcpy(&t, (char *)G->v[i]->data + v_wgt, sizeof(double)); + if (!(0.0 <= t && t <= (double)INT_MAX && t == floor(t))) + { ret = GLP_EDATA; + goto done; + } + w[i] = (int)t; + } + else + w[i] = 1; + s += (double)w[i]; + } + if (s > (double)INT_MAX) + { ret = GLP_EDATA; + goto done; + } + /* build the adjacency matrix */ + for (i = 1; i <= G->nv; i++) + { for (e = G->v[i]->in; e != NULL; e = e->h_next) + { j = e->tail->i; + /* there exists edge (j,i) in the graph */ + if (i > j) set_edge(G->nv, a, i, j); + } + for (e = G->v[i]->out; e != NULL; e = e->t_next) + { j = e->head->i; + /* there exists edge (i,j) in the graph */ + if (i > j) set_edge(G->nv, a, i, j); + } + } + /* find maximum weight clique in the graph */ + len = wclique(G->nv, w, a, ind); + /* compute the clique weight */ + s = 0.0; + for (k = 1; k <= len; k++) + { i = ind[k]; + xassert(1 <= i && i <= G->nv); + s += (double)w[i]; + } + if (sol != NULL) *sol = s; + /* mark vertices included in the clique */ + if (v_set >= 0) + { x = 0; + for (i = 1; i <= G->nv; i++) + memcpy((char *)G->v[i]->data + v_set, &x, sizeof(int)); + x = 1; + for (k = 1; k <= len; k++) + { i = ind[k]; + memcpy((char *)G->v[i]->data + v_set, &x, sizeof(int)); + } + } +done: /* free working arrays */ + xfree(w); + xfree(ind); + xfree(a); + return ret; +} + +/* eof */ |