def main(args):
stream = InStream(args[0])
G = Digraph.from_stream(stream)
tc = TransitiveClosure(G)
# print header
print(" ", end='')
for v in range(G.V()):
print("{x:3d}".format(x=v), end='')
print()
print("--------------------------------------------")
# print transitive closure
for v in range(G.V()):
print("{x:3d}: ".format(x=v), end='')
for w in range(G.V()):
if (tc.reachable(v, w)):
print(" T", end='')
else:
print(" ", end='')
print()
rev.add_edge(w, v)
return rev
def __repr__(self):
"""
Returns a string representation of this graph.
:returns: the number of vertices V, followed by the number of edges E,
followed by the V adjacency lists
"""
s = ["{} vertices, {} edges\n".format(self._V, self._E)]
for v in range(self._V):
s.append("%d : " % (v))
for w in self._adj[v]:
s.append("%d " % (w))
s.append("\n")
return ''.join(s)
import sys
if __name__ == '__main__':
# Create stream from file or the standard input,
# depending on whether a file name was passed.
stream = sys.argv[1] if len(sys.argv) > 1 else None
d = Digraph.from_stream(InStream(stream))
print(d)
return path
def _validateVertex(self, v):
# throw an ValueError unless 0 <= v < V
V = len(self._marked)
if v < 0 or v >= V:
raise ValueError("vertex {} is not between 0 and {}".format(
v, V - 1))
if __name__ == "__main__":
from algs4.stdlib import stdio
from algs4.graphs.graph import Graph
from algs4.stdlib.instream import InStream
import sys
In = InStream(sys.argv[1])
G = Graph.from_stream(In)
s = int(sys.argv[2])
dfs = DepthFirstPaths(G, s)
for v in range(G.V()):
if dfs.has_path_to(v):
stdio.writef("%d to %d: ", s, v)
for x in dfs.path_to(v):
if x == s: stdio.write(x)
else: stdio.writef("-%i", x)
stdio.writeln()
else:
stdio.writef("%d to %d: not connected\n", s, v)