chore: import upstream snapshot with attribution

2026-07-13 12:36:30 +08:00
commit 55ab4e4a73
473 changed files with 72932 additions and 0 deletions
@@ -0,0 +1,158 @@
+import unittest
+
+import easygraph as eg
+
+from easygraph.utils.exception import EasyGraphNotImplemented
+
+
+class test_bridges(unittest.TestCase):
+    def setUp(self):
+        self.g1 = eg.get_graph_karateclub()
+
+        # source graph: https://zh.wikipedia.org/zh-cn/%E6%88%B4%E5%85%8B%E6%96%AF%E7%89%B9%E6%8B%89%E7%AE%97%E6%B3%95#/media/File:Dijkstra_Animation.gif
+        edges = [(1, 2), (1, 3), (1, 6), (2, 3), (2, 4), (3, 4), (3, 6), (4, 5), (5, 6)]
+        self.g2 = eg.Graph(edges)
+        self.g2.add_edges(
+            edges,
+            edges_attr=[
+                {"weight": 7},
+                {"weight": 9},
+                {"weight": 14},
+                {"weight": 10},
+                {"weight": 15},
+                {"weight": 11},
+                {"weight": 2},
+                {"weight": 6},
+                {"weight": 9},
+            ],
+        )
+
+        # source graph: https://static.javatpoint.com/tutorial/daa/images/dijkstra-algorithm.png
+        self.g3 = eg.Graph()
+        edges = [
+            (0, 1),
+            (0, 4),
+            (1, 4),
+            (1, 2),
+            (4, 5),
+            (4, 8),
+            (2, 3),
+            (2, 6),
+            (2, 8),
+            (5, 6),
+            (5, 8),
+            (3, 6),
+            (3, 7),
+            (6, 7),
+        ]
+
+        self.g3.add_edges(
+            edges,
+            edges_attr=[
+                {"weight": 4},
+                {"weight": 1},
+                {"weight": 11},
+                {"weight": 8},
+                {"weight": 1},
+                {"weight": 7},
+                {"weight": 7},
+                {"weight": 4},
+                {"weight": 2},
+                {"weight": 2},
+                {"weight": 6},
+                {"weight": 14},
+                {"weight": 9},
+                {"weight": 10},
+            ],
+        )
+        self.g4 = eg.Graph()
+        edges = [(0, 1), (1, 2), (2, 3), (3, 0), (0, 2), (1, 3)]
+        self.g4.add_edges(
+            edges,
+            edges_attr=[
+                {"weight": -1},
+                {"weight": -2},
+                {"weight": -3},
+                {"weight": -4},
+                {"weight": -5},
+                {"weight": -6},
+            ],
+        )
+
+    def result(self, g: eg.Graph):
+        res = eg.bridges(g)
+        for i in res:
+            print(i)
+
+    def test_bridges(self):
+        self.result(g=self.g2)
+        self.result(g=self.g3)
+        self.result(g=self.g4)
+
+    def test_has_bridges(self):
+        print(eg.has_bridges(self.g2))
+
+    def test_empty_graph(self):
+        g = eg.Graph()
+        self.assertFalse(eg.has_bridges(g))
+        self.assertEqual(list(eg.bridges(g)), [])
+
+    def test_single_node_graph(self):
+        g = eg.Graph()
+        g.add_node(1)
+        self.assertFalse(eg.has_bridges(g))
+        self.assertEqual(list(eg.bridges(g)), [])
+
+    def test_disconnected_graph(self):
+        g = eg.Graph()
+        g.add_edges_from([(0, 1), (2, 3)])
+        self.assertTrue(eg.has_bridges(g))
+        self.assertCountEqual(list(eg.bridges(g)), [(0, 1), (2, 3)])
+
+    def test_cycle_graph(self):
+        g = eg.DiGraph([(1, 2), (2, 3), (3, 1)])
+        self.assertFalse(eg.has_bridges(g))
+        self.assertEqual(list(eg.bridges(g)), [])
+
+    def test_path_graph(self):
+        g = eg.path_graph(4)
+        self.assertTrue(eg.has_bridges(g))
+        self.assertCountEqual(list(eg.bridges(g)), [(0, 1), (1, 2), (2, 3)])
+
+    def test_star_graph(self):
+        g = eg.Graph()
+        g.add_edges_from([(0, i) for i in range(1, 5)])
+
+        expected = [(0, 1), (0, 2), (0, 3), (0, 4)]
+        self.assertTrue(eg.has_bridges(g))
+        self.assertCountEqual(list(eg.bridges(g)), expected)
+
+    def test_complete_graph(self):
+        g = eg.complete_graph(5)
+        self.assertFalse(eg.has_bridges(g))
+        self.assertEqual(list(eg.bridges(g)), [])
+
+    def test_graph_with_invalid_root(self):
+        g = eg.path_graph(3)
+        with self.assertRaises(eg.NodeNotFound):
+            list(eg.bridges(g, root=10))
+
+    def test_multigraph_exception(self):
+        g = eg.MultiGraph()
+        g.add_edges_from([(0, 1), (1, 2)])
+        with self.assertRaises(EasyGraphNotImplemented):
+            list(eg.bridges(g))
+        with self.assertRaises(EasyGraphNotImplemented):
+            eg.has_bridges(g)
+
+    def test_weighted_graph_should_ignore_weights(self):
+        g = eg.Graph()
+        g.add_edges_from(
+            [(0, 1), (1, 2), (2, 3), (3, 0)],
+            edges_attr=[{"weight": 10}, {"weight": 20}, {"weight": 30}, {"weight": 40}],
+        )
+        self.assertFalse(eg.has_bridges(g))
+
+
+if __name__ == "__main__":
+    unittest.main()