Add graph references

references/igraph-1.0.1/examples/simple/igraph_diameter.c

@@ -0,0 +1,56 @@
+/*
+   igraph library.
+   Copyright (C) 2024  The igraph development team <igraph@igraph.org>
+
+   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, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <igraph.h>
+
+int main(void) {
+
+    igraph_t graph;
+    igraph_real_t result;
+    igraph_int_t from, to;
+    igraph_vector_int_t path, path_edge;
+
+    /* Initialize the library. */
+    igraph_setup();
+
+    igraph_barabasi_game(&graph, 30, /*power=*/ 1, 30, 0, 0, /*A=*/ 1,
+                         IGRAPH_DIRECTED, IGRAPH_BARABASI_BAG,
+                         /*start_from=*/ NULL);
+    igraph_diameter(&graph, NULL, &result, NULL, NULL, NULL, NULL, IGRAPH_UNDIRECTED, 1);
+
+    /* printf("diameter: %g\n", result); */
+
+    igraph_destroy(&graph);
+
+    igraph_ring(&graph, 10, IGRAPH_DIRECTED, 0, 0);
+    igraph_vector_int_init(&path, 0);
+    igraph_vector_int_init(&path_edge, 0);
+    igraph_diameter(&graph, NULL, &result, &from, &to, &path, &path_edge, IGRAPH_DIRECTED, 1);
+    printf(
+        "diameter: %g, from %" IGRAPH_PRId " to %" IGRAPH_PRId "\n",
+        result, from, to
+    );
+    igraph_vector_int_print(&path);
+    igraph_vector_int_print(&path_edge);
+
+    igraph_vector_int_destroy(&path);
+    igraph_vector_int_destroy(&path_edge);
+    igraph_destroy(&graph);
+
+    return 0;
+}