Add graph references

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

@@ -0,0 +1,33 @@
+
+#include <igraph.h>
+#include <assert.h>
+
+int main(void) {
+    igraph_t graph;
+    igraph_vector_int_t edges;
+
+    /* Initialize the library. */
+    igraph_setup();
+
+    /* Create a directed graph with no vertices or edges. */
+    igraph_empty(&graph, 0, IGRAPH_DIRECTED);
+
+    /* Add 5 vertices. Vertex IDs will range from 0 to 4, inclusive. */
+    igraph_add_vertices(&graph, 5, NULL);
+
+    /* Add 5 edges, specified as 5 consecutive pairs of vertex IDs
+     * stored in an integer vector. */
+    igraph_vector_int_init_int(&edges, 10,
+                               0,1, 0,2, 3,1, 2,1, 0,4);
+    igraph_add_edges(&graph, &edges, NULL);
+
+    igraph_vector_int_destroy(&edges);
+
+    /* Now the graph has 5 vertices and 5 edges. */
+    assert(igraph_vcount(&graph) == 5);
+    assert(igraph_ecount(&graph) == 5);
+
+    igraph_destroy(&graph);
+
+    return 0;
+}