def test_depth_first_search_complex(capsys):
graph = Graph()
graph.graph['A'] = set()
graph.graph['B'] = set()
graph.graph['C'] = set()
graph.graph['D'] = set()
graph.graph['E'] = set()
graph.graph['F'] = set()
graph.graph['G'] = set()
graph.graph['H'] = set()
graph.add_edge('A', 'B')
graph.add_edge('A', 'C')
graph.add_edge('A', 'D')
graph.add_edge('B', 'E')
graph.add_edge('C', 'F')
graph.add_edge('C', 'G')
graph.add_edge('D', 'G')
graph.add_edge('E', 'H')
graph.add_edge('F', 'H')
graph.add_edge('G', 'H')
graph.depth_first_search('A')
expected = "A B E H F C G D "
output = capsys.readouterr().out
assert output == expected
def test_depth_first_search_one_node_graph(capsys):
graph = Graph()
graph.graph['A'] = set()
graph.depth_first_search('A')
expected = "A "
output = capsys.readouterr().out
assert output == expected
def test_depth_first_search_with_cycles(capsys):
graph = Graph()
graph.graph['A'] = set()
graph.graph['B'] = set()
graph.graph['C'] = set()
graph.graph['D'] = set()
graph.graph['E'] = set()
graph.add_edge('A', 'B')
graph.add_edge('A', 'C')
graph.add_edge('A', 'D')
graph.add_edge('A', 'E')
graph.add_edge('B', 'C')
graph.add_edge('C', 'D')
graph.add_edge('C', 'E')
graph.depth_first_search('A')
expected = "A B C D E "
output = capsys.readouterr().out
assert output == expected