+/*
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief Specialized implementation for perfect bipartite matching.
+ * @author Sebastian Hack
+ * @version $Id$
+ */
+#include "config.h"
#include <stdio.h>
#include <assert.h>
#include "bitset.h"
#include "bipartite.h"
+#include "xmalloc.h"
-struct _bipartite_t {
+struct bipartite_t {
int n_left, n_right;
- bitset_t **adj;
+ bitset_t *adj[1];
};
bipartite_t *bipartite_new(int n_left, int n_right)
{
+ bipartite_t *gr = XMALLOCFZ(bipartite_t, adj, n_left);
int i;
- bipartite_t *gr = malloc(sizeof(*gr));
- memset(gr, 0, sizeof(*gr));
gr->n_left = n_left;
gr->n_right = n_right;
- gr->adj = malloc(n_left * sizeof(void *));
- for(i = 0; i < n_left; ++i)
+ for (i = 0; i < n_left; ++i)
gr->adj[i] = bitset_malloc(n_right);
return gr;
void bipartite_free(bipartite_t *gr)
{
int i;
- for(i = 0; i < gr->n_left; ++i)
+ for (i = 0; i < gr->n_left; ++i)
bitset_free(gr->adj[i]);
-
- free(gr->adj);
free(gr);
}
{
int left, right;
int done_something = 0;
- bitset_t *tmp = bitset_malloc(gr->n_left);
+ bitset_t *tmp = bitset_alloca(gr->n_right);
- for(left = 0; left < gr->n_left; ++left) {
+ for (left = 0; left < gr->n_left; ++left) {
bitset_t *left_adj = gr->adj[left];
int i;
bitset_copy(tmp, left_adj);
- if(matching[left] >= 0) {
+ if (matching[left] >= 0) {
int old_right = matching[left];
/* Check of all neighbors of the left node are already matched.
* We cannot improve this edge then. */
- if(bitset_contains(left_adj, matched_right))
+ if (bitset_contains(left_adj, matched_right))
continue;
bitset_andnot(tmp, matched_right);
assert(right != -1);
- /* We have to find another left node which has the old right
- * one as a neighbor. */
- for(i = 0; i < gr->n_left; ++i)
- if(i != left && bitset_is_set(gr->adj[i], old_right))
+ /*
+ We have to find another left node which has the old right one as a neighbor.
+ This node must not be part of a matching
+ */
+ for (i = 0; i < gr->n_left; ++i)
+ if (i != left && bitset_is_set(gr->adj[i], old_right) && !bitset_is_set(matched_left, i))
break;
/* If no such node can be found, exit. */
- if(i >= gr->n_left)
+ if (i >= gr->n_left)
continue;
/* Else, we can improve this edge. */
assert(!bitset_is_set(matched_left, left));
bitset_andnot(tmp, matched_right);
- if(bitset_popcnt(tmp) == 0)
+ if (bitset_is_empty(tmp))
continue;
- right = bitset_min(tmp);
+ right = bitset_next_set(tmp, 0);
assert(!bitset_is_set(matched_right, right));
matching[left] = right;
bitset_set(matched_left, left);
}
}
- bitset_free(tmp);
-
return done_something;
}
void bipartite_matching(const bipartite_t *gr, int *matching)
{
- bitset_t *matched_left = bitset_malloc(gr->n_left);
- bitset_t *matched_right = bitset_malloc(gr->n_right);
+ bitset_t *matched_left = bitset_alloca(gr->n_left);
+ bitset_t *matched_right = bitset_alloca(gr->n_right);
memset(matching, -1, gr->n_left * sizeof(int));
- while(apply_alternating_path(gr, matching, matched_left, matched_right));
-
- bitset_free(matched_left);
- bitset_free(matched_right);
+ while (apply_alternating_path(gr, matching, matched_left, matched_right)) {
+ }
}
-void bipartite_dump(FILE *f, const bipartite_t *gr)
+void bipartite_dump_f(FILE *f, const bipartite_t *gr)
{
int i;
- for(i = 0; i < gr->n_left; ++i) {
+ for (i = 0; i < gr->n_left; ++i) {
+ fprintf(f, "%d: ", i);
bitset_fprint(f, gr->adj[i]);
fprintf(f, "\n");
}
}
+
+void bipartite_dump(const char *name, const bipartite_t *gr)
+{
+ FILE *f = fopen(name, "w");
+
+ if (f) {
+ bipartite_dump_f(f, gr);
+ fclose(f);
+ }
+}