aga,agar: Negative weight cycle testcase

[ccan] / ccan / agar / test / negacycle.c

diff --git a/ccan/agar/test/negacycle.c b/ccan/agar/test/negacycle.c
new file mode 100644 (file)
index 0000000..7d3daa9
--- /dev/null
+++ b/ccan/agar/test/negacycle.c
@@ -0,0 +1,42 @@
+#include "config.h"
+
+#include <assert.h>
+
+#include <ccan/container_of/container_of.h>
+#include <ccan/ptrint/ptrint.h>
+
+#include <ccan/agar/agar.h>
+
+#include "simple-graphr.h"
+
+static const void *negacycle_first_edge_r(const struct agar_graph *gr,
+                                         const void *nr)
+{
+       return int2ptr(1);
+}
+
+static const void *negacycle_next_edge_r(const struct agar_graph *gr,
+                                        const void *nr, const void *e)
+{
+       assert(ptr2int(e) == 1);
+       return NULL;
+}
+
+static int negacycle_edge_info_r(const struct agar_graph *gr,
+                                const void *nr, const void *e,
+                                struct agar_edge_info *eir)
+{
+       int ni = ptr2int(nr);
+
+       assert(ptr2int(e) == 1);
+       eir->to = int2ptr((ni % 3) + 1);
+       if (ni == 3)
+               eir->icost = -3;
+       return 0;
+}
+
+struct negacycle_graphr negacycle_graphr = {
+       AGAR_INIT_GRAPH(negacycle_first_edge_r,
+                       negacycle_next_edge_r,
+                       negacycle_edge_info_r),
+};