def set_graph(self, withWeights=False):
print "Please enter the number of vertices:\n"
num_vertices = raw_input(">")
print "Please enter the number of edges:\n"
num_edges = raw_input(">")
vertices = []
edges = []
for i in range(int(num_vertices)):
print "Please enter the name of the vertex: ", i
vertex_name = raw_input(">")
vertices.append(Vertex(vertex_name))
for j in range(int(num_edges)):
print "Please enter the name of the first vertex of edge\n"
first_vertex = raw_input(">")
print "Please enter the name of the second vertex of edge\n"
second_vertex = raw_input(">")
if withWeights:
print "Please enter edge weight\n"
edge_weight = raw_input(">")
edges.append(
Edge(Vertex(first_vertex), Vertex(second_vertex),
edge_weight))
else:
edges.append(Edge(Vertex(first_vertex), Vertex(second_vertex)))
return Graph(vertices=vertices, edges=edges)
def handle_shortest_path(self, g):
print "Enter the start vertex"
start_vertex = raw_input(">")
print "Enter the end vertex"
end_vertex = raw_input(">")
print "Your answer is ", g.find_shortest_path(Vertex(start_vertex),
Vertex(end_vertex))
def test_contains_cycle(self):
graph = self.createSampleGraph()
path = []
a_vertex = Vertex('A')
c_vertex = Vertex('C')
f_vertex = Vertex('F')
path.append(Edge(a_vertex, c_vertex, 1))
path.append(Edge(c_vertex, f_vertex, 2))
self.assertFalse(
graph.doesNotCreateCycle(path, Edge(f_vertex, c_vertex, 2)))
def test_get_visited_nodes_from_edge(self):
graph = self.create_undirected_graph()
path = [
Edge(Vertex('A'), Vertex('C')),
Edge(Vertex('B'), Vertex('C')),
Edge(Vertex('C'), Vertex('A'))
]
visited_nodes = graph.get_visited_nodes_from_edges(path)
correct_nodes = set([Vertex('A'), Vertex('B'), Vertex('C')])
self.assertEqual(visited_nodes, correct_nodes)
def test_dfs(self):
graph = self.createSampleGraph()
self.assertEquals([
Vertex('A'),
Vertex('C'),
Vertex('F'),
Vertex('E'),
Vertex('B'),
Vertex('D')
], graph.dfs(Vertex('A')))
def createSampleGraph(self):
vertices = []
a_vertex = Vertex('A')
b_vertex = Vertex('B')
c_vertex = Vertex('C')
d_vertex = Vertex('D')
e_vertex = Vertex('E')
f_vertex = Vertex('F')
vertices.append(a_vertex)
vertices.append(b_vertex)
vertices.append(c_vertex)
vertices.append(d_vertex)
vertices.append(e_vertex)
vertices.append(f_vertex)
edges = []
edges.append(Edge(a_vertex, c_vertex, 1))
edges.append(Edge(a_vertex, b_vertex, 3))
edges.append(Edge(b_vertex, d_vertex, 2))
edges.append(Edge(b_vertex, e_vertex, 2))
edges.append(Edge(c_vertex, f_vertex, 2))
edges.append(Edge(c_vertex, a_vertex, 2))
edges.append(Edge(d_vertex, b_vertex, 2))
edges.append(Edge(e_vertex, f_vertex, 2))
edges.append(Edge(e_vertex, b_vertex, 2))
edges.append(Edge(f_vertex, c_vertex, 2))
edges.append(Edge(f_vertex, e_vertex, 2))
graph = Graph(vertices, edges)
return graph
def test_prims_algo(self):
graph = self.create_undirected_graph()
a_vertex = Vertex('A')
b_vertex = Vertex('B')
c_vertex = Vertex('C')
d_vertex = Vertex('D')
e_vertex = Vertex('E')
f_vertex = Vertex('F')
expected_path = graph.prims_algorithm(Vertex('A'))
correct_path = [
Edge(a_vertex, c_vertex, 1),
Edge(c_vertex, f_vertex, 5),
Edge(f_vertex, e_vertex, 2),
Edge(e_vertex, b_vertex, 1),
Edge(b_vertex, d_vertex, 4)
]
self.assertEqual(expected_path, correct_path)
def handle_bfs(self, g):
print "Please enter what vertex you want to start from:\n"
start = raw_input(">")
print "Your answer is ", g.bfs(Vertex(start))
def handle_prims(self, g):
print "Please enter what vertex you want to start from:\n"
start = raw_input(">")
print "Your path is ", g.prims_algorithm(Vertex(start))
numberOfVertices = int(input("How many Vertices: "))
# we loop to add each vertex into a list to to insert the vertices in the alphabetical order
verticesList = []
i = 0
while i < numberOfVertices:
verLabel = input("Enter vertex number %d: " % (i + 1))
if verLabel not in verticesList:
verticesList.append(verLabel)
i += 1
else:
print("This vertex is already inserted")
verticesList.sort() # to sort the list
# adding all vertices into the graph
for i in verticesList:
graph.addVertex(Vertex(i))
print()
print("All vertices added successfully...")
# now we should add the edges
print()
numberOfEdges = int(input("How many Edges: "))
for i in range(0, numberOfEdges):
print()
addV = True
while addV:
ver1 = input("Enter Source label: ")
if ver1 not in verticesList:
print("This character is not in the graph")
else:
addV = False
def test_shortest_path(self):
graph = self.create_undirected_graph()
expected_path = graph.find_shortest_path(Vertex('A'), Vertex('E'))
correct_path = [Vertex('A'), Vertex('B'), Vertex('E')]
self.assertEqual(expected_path, correct_path)
def test_get_lowest_weight_edge(self):
graph = self.createSampleGraph()
path = []
edge = graph.getLowestWeightEdge(Vertex('A'), path)
self.assertEqual(Edge(Vertex('A'), Vertex('C'), 1), edge)
def test_edge_equality(self):
edge1 = Edge(Vertex('A'), Vertex('B'), 2)
edge2 = Edge(Vertex('A'), Vertex('B'), 2)
self.assertEqual(edge1, edge2)
def test_negative_kruskals_algo(self):
vertices = [Vertex('A'), Vertex('B'), Vertex('C')]
edges = [
Edge(Vertex('A'), Vertex('B'), 2),
Edge(Vertex('B'), Vertex('C'), 1),
Edge(Vertex('A'), Vertex('C'), 10)
]
graph = Graph(vertices, edges)
correct_path = graph.kruskals_algorithm()
incorrect_path = [
Edge(Vertex('B'), Vertex('C'), 1),
Edge(Vertex('A'), Vertex('B'), 10)
]
self.assertNotEqual(correct_path, incorrect_path)
def test_positive_kruskals_algo(self):
vertices = [Vertex('A'), Vertex('B'), Vertex('C')]
edges = [
Edge(Vertex('A'), Vertex('B'), 2),
Edge(Vertex('B'), Vertex('C'), 1),
Edge(Vertex('A'), Vertex('C'), 10)
]
graph = Graph(vertices, edges)
expected_path = graph.kruskals_algorithm()
correct_path = [
Edge(Vertex('B'), Vertex('C'), 1),
Edge(Vertex('A'), Vertex('B'), 2)
]
self.assertEqual(expected_path, correct_path)
