X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fagar%2Ftest%2Fsimple-graphr.h;h=21cae6a3497c9900ba010dd445f4acdd6203f649;hb=0ea6a2126c713207cb139d3329b15f0c9d735fbe;hp=2abe72dcb6903989fafa71d46b5c5f3715b95ab2;hpb=a2eaae42b58a44d6f88f5e20e4a7d7cdbde9edae;p=ccan

diff --git a/ccan/agar/test/simple-graphr.h b/ccan/agar/test/simple-graphr.h
index 2abe72dc..21cae6a3 100644
--- a/ccan/agar/test/simple-graphr.h
+++ b/ccan/agar/test/simple-graphr.h
@@ -19,7 +19,7 @@ struct adjacency_listr {
 struct trivial_graphr {
 	struct agar_graph gr;
 };
-void trivial_graphr_init(struct trivial_graphr *tgr);
+extern struct trivial_graphr trivial_graphr;
 static const struct adjacency_listr trivial_adjacencyr[] = {
 	{1, {}},
 	{},
@@ -156,7 +156,7 @@ static const struct adjacency_listr grid_adjacencyr_3x3_all[] = {
 struct error_graphr {
 	struct agar_graph gr;
 };
-void error_graphr_init(struct error_graphr *eg);
+extern struct error_graphr error_graphr;
 static const struct adjacency_listr error_adjacencyr[] = {
 	{1, {2}},
 	{2, {}},
@@ -185,7 +185,7 @@ static const struct adjacency_listr error_adjacencyr[] = {
 struct traversal1_graphr {
 	struct agar_graph gr;
 };
-void traversal1_graphr_init(struct traversal1_graphr *t1gr);
+extern struct traversal1_graphr traversal1_graphr;
 static const struct adjacency_listr traversal1_adjacency[] = {
 	{1, {2, 3}},
 	{2, {4, 5}},
@@ -199,4 +199,64 @@ static const struct adjacency_listr traversal1_adjacency[] = {
 	{},
 };
 
+/* Shortcut-1 graph
+ *
+ *   A ---- (3) -----> C
+ *    \             /
+ *     (1)-> B  --(1)
+ *
+ * This provides an example of a graph where the lowest cost path from
+ * (A) to (C) is not the path with the smallest number od edges.
+ */
+struct shortcut1_graphr {
+	struct agar_graph gr;
+};
+extern struct shortcut1_graphr shortcut1_graphr;
+static const struct adjacency_listr shortcut1_adjacencyr[] = {
+	{1, {3, 2}},
+	{2, {3}},
+	{3, {}},
+	{},
+};
+
+/* Shortcut-2 graph
+ *
+ *   A ---- (2) -----> C
+ *    \             /
+ *     (2)-> B  --(-1)
+ *
+ * This provides an example of a graph with a negative edge cost, but
+ * no negative cost cycles (and so still with well defined shortest
+ * paths).
+ */
+struct shortcut2_graphr {
+	struct agar_graph gr;
+};
+extern struct shortcut2_graphr shortcut2_graphr;
+static const struct adjacency_listr shortcut2_adjacencyr[] = {
+	{1, {3, 2}},
+	{2, {3}},
+	{3, {}},
+	{},
+};
+
+/* Negacycle graph
+ *
+ *  A <---- (-3) ----- C
+ *   \                 ^
+ *    (1)->  B -- (1)-/
+ *
+ * Graph with a negative length cycle, and so lacking well-defined shortest paths.
+ */
+struct negacycle_graphr {
+	struct agar_graph gr;
+};
+extern struct negacycle_graphr negacycle_graphr;
+static const struct adjacency_listr negacycle_adjacencyr[] = {
+	{1, {2}},
+	{2, {3}},
+	{3, {1}},
+	{},
+};
+
 #endif /* _SIMPLE_GRAPHR_H */