WHITE = "WHITE"

BLACK = "BLACK"

GREY = "GREY"

TIME = 0

class Vertex:

def __init__(self, key):

self.key = key

self.adjlist = {}

def display(self):

print "Key = %s\tEdges = %s" % (self.key, str(self.adjlist.keys()))

def __repr__(self):

return "%s: %s" % (str(self.key), str(self.adjlist.keys()))

class Graph:

def __init__(self):

self.vertices = {}

def add_vertex(self, key):

self.vertices[key] = Vertex(key)

def add_directed_edge(self, fromv, tov, weight):

self.vertices[fromv].adjlist[tov] = weight

def add_undirected_edge(self, fromv, tov, weight):

self.add_directed_edge(fromv, tov, weight)

self.add_directed_edge(tov, fromv, weight)

def create(self):

print "Graph creation helper"

directed = False

directedq = raw_input("Is this a directed graph (y or n)?")

if directedq.lower() == 'y':

directed = True

while 1:

v = raw_input("Enter Vertex key, hit 'q' when finished:\t")

if v=='q':

break

self.add_vertex(v)

while 1:

s = raw_input("Starting vertex ('q' to exit):\t")

if (s == 'q'):

break

e = raw_input("Ending vertex:\t")

if directed:

self.add_directed_edge(s,e,1)

else:

self.add_undirected_edge(s,e,1)

def display(self):

for vert in self.vertices.values():

vert.display()

def dfs_visit(self, vert, verbose, list):

global TIME

TIME += 1

vert.d = TIME

vert.color = GREY

for v in vert.adjlist.keys():

u = self.vertices[v]

if u.color == WHITE:

u.parent = vert

list = self.dfs_visit(u, verbose, list)

vert.color = BLACK

list.append(vert)

if verbose:

print "Visited " + str(vert.key)

TIME += 1

vert.f = TIME

return list

def dfs(self, verbose):

global TIME

list = []

for vert in self.vertices.values():

vert.color = WHITE

vert.parent = None

vert.d = -1

vert.f = -1

TIME = 0

for vert in self.vertices.values():

if vert.color == WHITE:

list = self.dfs_visit(vert, verbose, list)

return list

def bfs(self, vertex, target):

visited = []

self.vertices[vertex].d = 0

queue = [self.vertices[vertex]]

d = 0

while len(queue) > 0:

u = queue[0]

visited.append(u)

if u.key == target:

return (u, d)

queue = queue[1:]

for v in u.adjlist.keys():

vert = self.vertices[v]

if ((vert not in visited) and (vert not in queue)):

print "Adding %s to queue" % vert

queue.append(vert)

d += 1

if __name__ == "__main__":

g = Graph()

g.create()

g.display()

#print g.bfs('1','3')

print g.dfs(True)