trac #27859: add test on random digraphs

sagemath · Aug 3, 2019 · 3ae912d · 3ae912d
1 parent 7c9bc30
commit 3ae912d
Showing 1 changed file with 17 additions and 0 deletions.
diff --git a/src/sage/graphs/path_enumeration.pyx b/src/sage/graphs/path_enumeration.pyx
@@ -500,6 +500,23 @@ def shortest_simple_paths(self, source, target, weight_function=None,
         sage: s == t
         True
 
+    Check that "Yen" and "Feng" provide same results on random digraphs::
+
+        sage: G = digraphs.RandomDirectedGNP(30, .05)
+        sage: while not G.is_strongly_connected():
+        ....:     G = digraphs.RandomDirectedGNP(30, .1)
+        sage: for u, v in list(G.edges(labels=False, sort=False)):
+        ....:     G.set_edge_label(u, v, randint(1, 10))
+        sage: V = G.vertices()
+        sage: shuffle(V)
+        sage: u, v = V[:2]
+        sage: it_Y = G.shortest_simple_paths(u, v, by_weight=True, report_weight=True, algorithm='Yen')
+        sage: it_F = G.shortest_simple_paths(u, v, by_weight=True, report_weight=True, algorithm='Feng')
+        sage: for i, (y, f) in enumerate(zip(it_Y, it_F)):
+        ....:     if y[0] != f[0]:
+        ....:         raise ValueError("something goes wrong !")
+        ....:     if i == 100:
+        ....:         break
     """
     if source not in self:
         raise ValueError("vertex '{}' is not in the graph".format(source))