def _simple(self, V: int, p: float) -> Digraph:
if p < 0.0 or p > 1.0:
raise ValueError("Probability must be between 0 and 1")
g = Digraph(V)
for v in range(V):
for w in range(V):
if v != w:
if random.uniform() < p:
g.add_edge(v, w)
return g
def main():
import os
from stdlib.utils.inn import In
dirpath = os.getcwd()
inn = In('{0}/tests/tinyDG.txt'.format(dirpath))
g = Digraph(inn=inn)
dfs = DepthFirstOrder(G=g)
print(" v pre post")
print("--------------")
s = ''
for v in range(g.V):
s += '\t{} \t{} \t{}\n'.format(v, dfs.pre(v), dfs.post(v))
s += 'Preorder: '
for v in dfs.pre():
s += '{} '.format(v)
s += '\nPostorder: '
for v in dfs.post():
s += '{} '.format(v)
s += '\nReverse postorder: '
for v in dfs.reverse_post():
s += '{} '.format(v)
print(s)
def simple(self, V: int, E: int) -> Digraph:
if E > V * (V - 1):
raise ValueError("Too many edges")
if E < 0:
raise ValueError("Too few edges")
g = Digraph(V)
s = set()
while g.E < E:
v = random.uniform(V)
w = random.uniform(V)
e = Edge(v, w)
if v != w and e not in s:
s.add(e)
g.add_edge(v, w)
return g
def dag(self, V: int, E: int) -> Digraph:
if E > V * (V - 1) / 2:
raise ValueError("Too many edges")
if E < 0:
raise ValueError("Too few edges")
g = Digraph(V)
s = set()
vertices = [i for i in range(V)]
random.shuffle(vertices)
while g.E < E:
v = random.uniform(V)
w = random.uniform(V)
e = Edge(v, w)
if v < w and e not in s:
s.add(e)
g.add_edge(vertices[v], vertices[w])
return g
def tournament(self, V: int) -> Digraph:
g = Digraph(V)
for v in range(g.V):
for w in range(v + 1, g.V):
if random.uniform() < 0.5:
g.add_edge(v, w)
else:
g.add_edge(w, v)
return g
def dfs(self, v: int, G: Digraph = None, EWG: EdgeWeightedDigraph = None):
if not G and not EWG:
raise ValueError("You have to provide a digraph or edge weighted digraph")
self._marked[v] = True
self._pre[v] = self._pre_counter
self._pre_counter += 1
self._preorder.enqueue(v)
if G:
for w in G.adj(v):
if not self._marked[w]:
self.dfs(w, G=G)
elif EWG:
for e in EWG.adj(v):
w = e.to()
if not self._marked[w]:
self.dfs(w, EWG=EWG)
self._postorder.enqueue(v)
self._post[v] = self._post_counter
self._post_counter += 1
def main():
import os
from stdlib.utils.inn import In
dir_path = os.getcwd()
inn = In('{0}/tests/tinyDG.txt'.format(dir_path))
s = 1
g = Digraph(inn=inn)
dfs = DepthFirstDirectedPaths(g, s)
string = ''
for v in range(g.V):
if dfs.has_path_to(v):
string += '{0} to {1}: '.format(s, v)
for x in dfs.path_to(v):
if x == s:
string += x.__str__()
else:
string += "-{0}".format(x)
string += '\n'
else:
string += "{0} to {1}: not connected\n".format(s, v)
print(string)
def __dfs(self, G: Digraph, v: int) -> None:
self._marked[v] = True
for w in G.adj(v):
if not self._marked[w]:
self._edge_to[w] = v
self.__dfs(G, w)