Spaces:
Running
Running
| import networkx as nx | |
| def test_unionfind(): | |
| # Fixed by: 2cddd5958689bdecdcd89b91ac9aaf6ce0e4f6b8 | |
| # Previously (in 2.x), the UnionFind class could handle mixed types. | |
| # But in Python 3.x, this causes a TypeError such as: | |
| # TypeError: unorderable types: str() > int() | |
| # | |
| # Now we just make sure that no exception is raised. | |
| x = nx.utils.UnionFind() | |
| x.union(0, "a") | |
| def test_subtree_union(): | |
| # See https://github.com/networkx/networkx/pull/3224 | |
| # (35db1b551ee65780794a357794f521d8768d5049). | |
| # Test if subtree unions hare handled correctly by to_sets(). | |
| uf = nx.utils.UnionFind() | |
| uf.union(1, 2) | |
| uf.union(3, 4) | |
| uf.union(4, 5) | |
| uf.union(1, 5) | |
| assert list(uf.to_sets()) == [{1, 2, 3, 4, 5}] | |
| def test_unionfind_weights(): | |
| # Tests if weights are computed correctly with unions of many elements | |
| uf = nx.utils.UnionFind() | |
| uf.union(1, 4, 7) | |
| uf.union(2, 5, 8) | |
| uf.union(3, 6, 9) | |
| uf.union(1, 2, 3, 4, 5, 6, 7, 8, 9) | |
| assert uf.weights[uf[1]] == 9 | |
| def test_unbalanced_merge_weights(): | |
| # Tests if the largest set's root is used as the new root when merging | |
| uf = nx.utils.UnionFind() | |
| uf.union(1, 2, 3) | |
| uf.union(4, 5, 6, 7, 8, 9) | |
| assert uf.weights[uf[1]] == 3 | |
| assert uf.weights[uf[4]] == 6 | |
| largest_root = uf[4] | |
| uf.union(1, 4) | |
| assert uf[1] == largest_root | |
| assert uf.weights[largest_root] == 9 | |
| def test_empty_union(): | |
| # Tests if a null-union does nothing. | |
| uf = nx.utils.UnionFind((0, 1)) | |
| uf.union() | |
| assert uf[0] == 0 | |
| assert uf[1] == 1 | |