def test_simple_pass(self):
"""Cyclic graphs are connected 2A and 2E."""
g = UG()
g.addpath(0, 1)
g.addpath(1, 2)
g.addpath(2, 0)
self.assertTrue(g.checkconnectivity_2A())
self.assertTrue(g.checkconnectivity_2E())
def test_simple_fail(self):
"""A cycle makes a graph 2E, but not necessarily 2A."""
g = UG()
g.addpath(0, 1)
g.addpath(1, 2)
g.addpath(2, 0)
g.addpath(3, 0)
self.assertFalse(g.checkconnectivity_2A())
self.assertTrue(g.checkconnectivity_2E())
def test_textbook_fail(self):
"""Textbook example modified to be not 2E or 2A connected."""
g = UG()
g.addpath('a', 'b')
g.addpath('b', 'e')
g.addpath('e', 'd')
g.addpath('d', 'c')
g.addpath('e', 'f')
g.addpath('e', 'h')
g.addpath('f', 'g')
g.addpath('f', 'i')
g.addpath('i', 'j')
g.addpath('i', 'm')
g.addpath('m', 'k')
g.addpath('k', 'l')
self.assertFalse(g.checkconnectivity_2A()) # False
self.assertFalse(g.checkconnectivity_2E()) # False
def test_textbook_pass2E(self):
"""Textbook example of 2E connectedness."""
g = UG()
g.addpath('a', 'b')
g.addpath('b', 'e')
g.addpath('e', 'd')
g.addpath('d', 'c')
g.addpath('e', 'f')
g.addpath('e', 'h')
g.addpath('f', 'g')
g.addpath('f', 'i')
g.addpath('i', 'j')
g.addpath('i', 'm')
g.addpath('m', 'k')
g.addpath('k', 'l')
g.addpath('g', 'h')
self.assertFalse(g.checkconnectivity_2A()) # False
self.assertTrue(g.checkconnectivity_2E()) # True
def test_trivial_pass_zero(self):
"""Graphs with zero nodes are automatically very connected."""
g = UG()
self.assertTrue(g.checkconnectivity_2A())
self.assertTrue(g.checkconnectivity_2E())
def test_trivial_fail(self):
"""With just two nodes and one path, this isn't very connected."""
g = UG()
g.addpath(0, 1)
self.assertFalse(g.checkconnectivity_2A())
self.assertFalse(g.checkconnectivity_2E())
def test_trivial_pass_one(self):
"""Graphs with one node are automatically very connected."""
g = UG()
g.addnode(42)
self.assertTrue(g.checkconnectivity_2A())
self.assertTrue(g.checkconnectivity_2E())