two version of R2R are hereHEADmaster

1 files changed, 85 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/networkx/algorithms/tests/test_covering.py b/.venv/lib/python3.12/site-packages/networkx/algorithms/tests/test_covering.py
new file mode 100644
index 00000000..b2f97a86
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/networkx/algorithms/tests/test_covering.py
@@ -0,0 +1,85 @@
+import pytest
+
+import networkx as nx
+
+
+class TestMinEdgeCover:
+    """Tests for :func:`networkx.algorithms.min_edge_cover`"""
+
+    def test_empty_graph(self):
+        G = nx.Graph()
+        assert nx.min_edge_cover(G) == set()
+
+    def test_graph_with_loop(self):
+        G = nx.Graph()
+        G.add_edge(0, 0)
+        assert nx.min_edge_cover(G) == {(0, 0)}
+
+    def test_graph_with_isolated_v(self):
+        G = nx.Graph()
+        G.add_node(1)
+        with pytest.raises(
+            nx.NetworkXException,
+            match="Graph has a node with no edge incident on it, so no edge cover exists.",
+        ):
+            nx.min_edge_cover(G)
+
+    def test_graph_single_edge(self):
+        G = nx.Graph([(0, 1)])
+        assert nx.min_edge_cover(G) in ({(0, 1)}, {(1, 0)})
+
+    def test_graph_two_edge_path(self):
+        G = nx.path_graph(3)
+        min_cover = nx.min_edge_cover(G)
+        assert len(min_cover) == 2
+        for u, v in G.edges:
+            assert (u, v) in min_cover or (v, u) in min_cover
+
+    def test_bipartite_explicit(self):
+        G = nx.Graph()
+        G.add_nodes_from([1, 2, 3, 4], bipartite=0)
+        G.add_nodes_from(["a", "b", "c"], bipartite=1)
+        G.add_edges_from([(1, "a"), (1, "b"), (2, "b"), (2, "c"), (3, "c"), (4, "a")])
+        # Use bipartite method by prescribing the algorithm
+        min_cover = nx.min_edge_cover(
+            G, nx.algorithms.bipartite.matching.eppstein_matching
+        )
+        assert nx.is_edge_cover(G, min_cover)
+        assert len(min_cover) == 8
+        # Use the default method which is not specialized for bipartite
+        min_cover2 = nx.min_edge_cover(G)
+        assert nx.is_edge_cover(G, min_cover2)
+        assert len(min_cover2) == 4
+
+    def test_complete_graph_even(self):
+        G = nx.complete_graph(10)
+        min_cover = nx.min_edge_cover(G)
+        assert nx.is_edge_cover(G, min_cover)
+        assert len(min_cover) == 5
+
+    def test_complete_graph_odd(self):
+        G = nx.complete_graph(11)
+        min_cover = nx.min_edge_cover(G)
+        assert nx.is_edge_cover(G, min_cover)
+        assert len(min_cover) == 6
+
+
+class TestIsEdgeCover:
+    """Tests for :func:`networkx.algorithms.is_edge_cover`"""
+
+    def test_empty_graph(self):
+        G = nx.Graph()
+        assert nx.is_edge_cover(G, set())
+
+    def test_graph_with_loop(self):
+        G = nx.Graph()
+        G.add_edge(1, 1)
+        assert nx.is_edge_cover(G, {(1, 1)})
+
+    def test_graph_single_edge(self):
+        G = nx.Graph()
+        G.add_edge(0, 1)
+        assert nx.is_edge_cover(G, {(0, 0), (1, 1)})
+        assert nx.is_edge_cover(G, {(0, 1), (1, 0)})
+        assert nx.is_edge_cover(G, {(0, 1)})
+        assert not nx.is_edge_cover(G, {(0, 0)})