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 +1,143 @@
+import unittest
+
+import easygraph as eg
+
+
+class test_diameter(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.DiGraph()
+        edges = [(0, 1), (1, 2), (2, 3), (3, 0), (0, 2), (1, 3), (1, 0)]
+        self.g4.add_edges(
+            edges,
+            edges_attr=[
+                {"weight": 1},
+                {"weight": 2},
+                {"weight": 3},
+                {"weight": 4},
+                {"weight": 5},
+                {"weight": 6},
+                {"weight": 11},
+            ],
+        )
+
+    def test_diameter(self):
+        print(eg.diameter(self.g2))
+        print(eg.diameter(self.g3))
+        print(eg.diameter(self.g4))
+
+    def test_eccentricity(self):
+        print(eg.eccentricity(self.g2, list(self.g2.nodes.keys())[0:-1]))
+        print(eg.eccentricity(self.g3))
+        print(eg.eccentricity(self.g4))
+
+    def test_single_node_graph(self):
+        G = eg.Graph()
+        G.add_node(1)
+        self.assertEqual(eg.eccentricity(G), {1: 0})
+        self.assertEqual(eg.diameter(G), 0)
+
+    def test_two_node_graph(self):
+        G = eg.Graph([(1, 2)])
+        self.assertEqual(eg.eccentricity(G), {1: 1, 2: 1})
+        self.assertEqual(eg.diameter(G), 1)
+
+    def test_disconnected_graph(self):
+        G = eg.Graph()
+        G.add_nodes_from([1, 2, 3])
+        G.add_edge(1, 2)
+        with self.assertRaises(eg.EasyGraphError):
+            eg.eccentricity(G)
+
+    def test_directed_not_strongly_connected(self):
+        G = eg.DiGraph()
+        G.add_edges_from([(1, 2), (2, 3)])  # Not strongly connected
+        with self.assertRaises(eg.EasyGraphError):
+            eg.eccentricity(G)
+
+    def test_eccentricity_with_sp(self):
+        G = eg.Graph([(1, 2), (2, 3)])
+        sp = {
+            1: {1: 0, 2: 1, 3: 2},
+            2: {2: 0, 1: 1, 3: 1},
+            3: {3: 0, 2: 1, 1: 2},
+        }
+        self.assertEqual(eg.eccentricity(G, sp=sp), {1: 2, 2: 1, 3: 2})
+        self.assertEqual(eg.diameter(G, e=eg.eccentricity(G, sp=sp)), 2)
+
+    def test_eccentricity_single_node_query(self):
+        G = eg.Graph([(1, 2), (2, 3)])
+        self.assertEqual(eg.eccentricity(G, v=1), 2)
+        self.assertEqual(eg.eccentricity(G, v=2), 1)
+
+    def test_eccentricity_subset_of_nodes(self):
+        G = eg.Graph([(1, 2), (2, 3)])
+        result = eg.eccentricity(G, v=[1, 3])
+        self.assertEqual(result[1], 2)
+        self.assertEqual(result[3], 2)
+
+    def test_diameter_matches_max_eccentricity(self):
+        G = eg.Graph([(1, 2), (2, 3)])
+        ecc = eg.eccentricity(G)
+        self.assertEqual(eg.diameter(G, e=ecc), max(ecc.values()))
+
+
+if __name__ == "__main__":
+    unittest.main()