Add graph references

2026-06-28 13:49:01 +01:00
parent 0a9807e448
commit a11edf0c53
2578 changed files with 868045 additions and 0 deletions
@@ -0,0 +1,139 @@
+/*
+   igraph library.
+   Copyright (C) 2006-2012  Gabor Csardi <csardi.gabor@gmail.com>
+   334 Harvard street, Cambridge, MA 02139 USA
+
+   This program 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 2 of the License, or
+   (at your option) any later version.
+
+   This program 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 this program; if not, write to the Free Software
+   Foundation, Inc.,  51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA
+
+*/
+
+#include <igraph.h>
+
+int main(void) {
+    igraph_t orig, sub, diff;
+    igraph_vector_int_t v;
+
+    /* Initialize the library. */
+    igraph_setup();
+
+    /* Subtract from itself */
+    printf("subtract itself\n");
+    igraph_vector_int_init_int_end(&v, -1, 0, 1, 1, 2, 2, 1, 4, 5, -1);
+    igraph_create(&orig, &v, 0, IGRAPH_DIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_difference(&diff, &orig, &orig);
+    igraph_write_graph_edgelist(&diff, stdout);
+    if (igraph_ecount(&diff) != 0 ||
+        igraph_vcount(&diff) != igraph_vcount(&orig)) {
+        return 1;
+    }
+
+    igraph_destroy(&orig);
+    igraph_destroy(&diff);
+
+    /* Same for undirected graph */
+    printf("subtract itself, undirected\n");
+    igraph_vector_int_init_int_end(&v, -1, 0, 1, 1, 2, 2, 1, 4, 5, -1);
+    igraph_create(&orig, &v, 0, IGRAPH_UNDIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_vector_int_init_int_end(&v, -1, 1, 0, 1, 2, 2, 1, 4, 5, -1);
+    igraph_create(&sub, &v, 0, IGRAPH_UNDIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_difference(&diff, &orig, &sub);
+    igraph_write_graph_edgelist(&diff, stdout);
+    if (igraph_ecount(&diff) != 0 ||
+        igraph_vcount(&diff) != igraph_vcount(&orig)) {
+        return 2;
+    }
+
+    igraph_destroy(&orig);
+    igraph_destroy(&sub);
+    igraph_destroy(&diff);
+
+    /* Subtract the empty graph */
+    printf("subtract empty\n");
+    igraph_vector_int_init_int_end(&v, -1, 0, 1, 1, 2, 2, 1, 4, 5, -1);
+    igraph_create(&orig, &v, 0, IGRAPH_DIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_empty(&sub, 3, IGRAPH_DIRECTED);
+    igraph_difference(&diff, &orig, &sub);
+    igraph_write_graph_edgelist(&diff, stdout);
+    if (igraph_ecount(&diff) != igraph_ecount(&orig) ||
+        igraph_vcount(&diff) != igraph_vcount(&orig)) {
+        return 3;
+    }
+
+    igraph_destroy(&orig);
+    igraph_destroy(&sub);
+    igraph_destroy(&diff);
+
+    /* A `real' example */
+    printf("real example\n");
+    igraph_vector_int_init_int_end(&v, -1, 0, 1, 1, 2, 2, 1, 4, 5, 8, 9, -1);
+    igraph_create(&orig, &v, 0, IGRAPH_DIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_vector_int_init_int_end(&v, -1, 0, 1, 5, 4, 2, 1, 6, 7, -1);
+    igraph_create(&sub, &v, 0, IGRAPH_DIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_difference(&diff, &orig, &sub);
+    igraph_write_graph_edgelist(&diff, stdout);
+
+    igraph_destroy(&diff);
+    igraph_destroy(&orig);
+    igraph_destroy(&sub);
+
+    /* undirected version */
+    printf("real example, undirected\n");
+    igraph_vector_int_init_int_end(&v, -1, 0, 1, 1, 2, 2, 1, 4, 5, 8, 9, 8, 10, 8, 13, 8, 11, 8, 12, -1);
+    igraph_create(&orig, &v, 0, IGRAPH_UNDIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_vector_int_init_int_end(&v, -1, 0, 1, 5, 4, 2, 1, 6, 7, 8, 10, 8, 13, -1);
+    igraph_create(&sub, &v, 0, IGRAPH_UNDIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_difference(&diff, &orig, &sub);
+    igraph_write_graph_edgelist(&diff, stdout);
+
+    igraph_destroy(&diff);
+    igraph_destroy(&orig);
+    igraph_destroy(&sub);
+
+    /* undirected version with loop edge, tests Github issue #597 */
+    printf("Github issue #597, undirected\n");
+    igraph_vector_int_init_int_end(&v, -1, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 0, -1);
+    igraph_create(&orig, &v, 0, IGRAPH_UNDIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_vector_int_init_int_end(&v, -1, 0, 1, 1, 2, 2, 3, 3, 4, 4, 0, -1);
+    igraph_create(&sub, &v, 0, IGRAPH_UNDIRECTED);
+    igraph_vector_int_destroy(&v);
+
+    igraph_difference(&diff, &orig, &sub);
+    igraph_write_graph_edgelist(&diff, stdout);
+
+    igraph_destroy(&diff);
+    igraph_destroy(&orig);
+    igraph_destroy(&sub);
+
+    return 0;
+}