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 +1,159 @@
+/*
+   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>
+
+#include "../unit/test_utilities.h"
+
+/* Regression test for https://github.com/igraph/igraph/issues/1760 */
+
+int test_unweighted(const igraph_t* g, igraph_int_t from, const igraph_vs_t* to) {
+    igraph_vector_int_list_t vpath, epath;
+    igraph_int_t num_paths;
+    igraph_vector_int_t parents;
+    igraph_vector_int_t inbound_edges;
+
+    printf("Unweighted case\n");
+    printf("---------------\n\n");
+
+    IGRAPH_CHECK(igraph_vs_size(g, to, &num_paths));
+    IGRAPH_CHECK(igraph_vector_int_list_init(&vpath, 0));
+    IGRAPH_CHECK(igraph_vector_int_list_init(&epath, 0));
+    IGRAPH_CHECK(igraph_vector_int_init(&parents, 0));
+    IGRAPH_CHECK(igraph_vector_int_init(&inbound_edges, 0));
+
+    IGRAPH_CHECK(igraph_get_shortest_paths(
+        g, NULL, &vpath, &epath, from, *to, IGRAPH_IN,
+        &parents, &inbound_edges
+    ));
+
+    printf("Vertices:\n");
+    print_vector_int_list(&vpath);
+    printf("\n");
+
+    printf("Edges:\n");
+    print_vector_int_list(&epath);
+    printf("\n");
+
+    printf("Parents:\n");
+    print_vector_int(&parents);
+    printf("\n");
+
+    printf("Inbound edges:\n");
+    print_vector_int(&inbound_edges);
+    printf("\n");
+
+    igraph_vector_int_destroy(&inbound_edges);
+    igraph_vector_int_destroy(&parents);
+    igraph_vector_int_list_destroy(&epath);
+    igraph_vector_int_list_destroy(&vpath);
+
+    return IGRAPH_SUCCESS;
+}
+
+int test_weighted(
+    const igraph_t* g, const igraph_vector_t* weights, igraph_int_t from,
+    const igraph_vs_t* to, igraph_bool_t use_bellman_ford
+) {
+    igraph_vector_int_list_t vpath, epath;
+    igraph_int_t num_paths;
+    igraph_vector_int_t parents;
+    igraph_vector_int_t inbound_edges;
+
+    printf("Weighted case\n");
+    printf("-------------\n\n");
+
+    printf("Algorithm: %s\n\n", use_bellman_ford ? "Bellman-Ford" : "Dijkstra");
+
+    IGRAPH_CHECK(igraph_vs_size(g, to, &num_paths));
+    IGRAPH_CHECK(igraph_vector_int_list_init(&vpath, 0));
+    IGRAPH_CHECK(igraph_vector_int_list_init(&epath, 0));
+    IGRAPH_CHECK(igraph_vector_int_init(&parents, 0));
+    IGRAPH_CHECK(igraph_vector_int_init(&inbound_edges, 0));
+
+    if (use_bellman_ford) {
+        IGRAPH_CHECK(igraph_get_shortest_paths_bellman_ford(
+            g, &vpath, &epath, from, *to, weights, IGRAPH_IN,
+            &parents, &inbound_edges
+        ));
+    } else {
+        IGRAPH_CHECK(igraph_get_shortest_paths_dijkstra(
+            g, &vpath, &epath, from, *to, weights, IGRAPH_IN,
+            &parents, &inbound_edges
+        ));
+    }
+
+    printf("Vertices:\n");
+    print_vector_int_list(&vpath);
+    printf("\n");
+
+    printf("Edges:\n");
+    print_vector_int_list(&epath);
+    printf("\n");
+
+    printf("Parents:\n");
+    print_vector_int(&parents);
+    printf("\n");
+
+    printf("Inbound edges:\n");
+    print_vector_int(&inbound_edges);
+    printf("\n");
+
+    igraph_vector_int_destroy(&inbound_edges);
+    igraph_vector_int_destroy(&parents);
+    igraph_vector_int_list_destroy(&epath);
+    igraph_vector_int_list_destroy(&vpath);
+
+    return IGRAPH_SUCCESS;
+}
+
+int main(void) {
+    igraph_t g;
+    igraph_vector_t weights;
+    igraph_vs_t to;
+
+    igraph_set_warning_handler(igraph_warning_handler_ignore);
+
+    igraph_small(&g, 4, /* directed = */ 1, 0, 1, 1, 2, 1, 3, -1);
+    igraph_vs_vector_small(&to, 0, 3, -1);
+    igraph_vector_init(&weights, 3);
+    VECTOR(weights)[0] = 1;
+    VECTOR(weights)[1] = 2;
+    VECTOR(weights)[2] = 2;
+
+    /* Test unweighted case */
+    if (test_unweighted(&g, 2, &to)) {
+        return 1;
+    }
+
+    /* Test weighted case */
+    if (test_weighted(&g, &weights, 2, &to, /* use_bellman_ford = */ 0)) {
+        return 2;
+    }
+    if (test_weighted(&g, &weights, 2, &to, /* use_bellman_ford = */ 1)) {
+        return 3;
+    }
+
+    igraph_vector_destroy(&weights);
+    igraph_vs_destroy(&to);
+    igraph_destroy(&g);
+
+    VERIFY_FINALLY_STACK();
+
+    return 0;
+}