def edges(self):
"""
Returns all directed edges in this edge-weighted digraph.
:return: all edges in this edge-weighted digraph
:rtype: collections.iterable[DirectedEdge]
"""
edges = Bag()
for v in range(self._V):
for e in self._adj[v]:
edges.add(e)
return edges
def main():
"""Unit tests the DirectedDFS data type."""
G = Digraph.from_stream(InStream(None))
sources = Bag()
for i in range(1, len(sys.argv)):
s = int(sys.argv[i])
sources.add(s)
dfs = DirectedDFS(G, *sources)
print("Reachable vertices:")
for v in range(0, G.V()):
if dfs.is_marked(v):
print(v, end=" ")
print()
def __init__(self, V, E):
self._V = V
self._E = E
self._adj = []
for _ in range(V):
self._adj.append(Bag())
def __init__(self, V):
self._V = V
self._E = 0
self._indegree = [0] * V
self._adj = [None] * V
for v in range(V):
self._adj[v] = Bag()
def __init__(self, V):
if V < 0:
raise ValueError("Number of vertices must be nonnegative")
self._V = V
self._E = 0
self._adj = [] # adjacency lists
for _ in range(V):
self._adj.append(Bag()) # Initialize all lists to empty bags.
def __init__(self, V):
"""
Initializes an empty edge-weighted graph with V vertices and 0 edges.
:param V: the number of vertices
:raises IllegalArgumentException: if V < 0
"""
if V < 0:
raise IllegalArgumentException(
"Number of vertices must be nonnegative")
self._V = V
self._E = 0
self._adj = [None] * V
for v in range(V):
self._adj[v] = Bag()
def __init__(self, V):
"""
Initializes an empty graph with V vertices and 0 edges.
param V the number of vertices
:param V: number of vertices
:raises: ValueError if V < 0
"""
if V < 0: raise ValueError("Number of vertices must be nonnegative")
self._V = V # number of vertices
self._E = 0 # number of edges
self._adj = [] # adjacency lists
for _ in range(V):
self._adj.append(Bag()) # Initialize all lists to empty bags.
def edges(self):
"""
Returns all edges in this edge-weighted graph.
:return: all edges in this edge-weighted graph
"""
edges = Bag()
for v in range(self._V):
self_loops = 0
for e in self.adj(v):
if e.other(v) > v:
edges.add(e)
elif e.other(v) is v:
if self_loops % 2 is 0:
edges.add(e)
self_loops += 1
return edges
def __init__(self, V):
self._V = V
self._E = 0
self._adj = [Bag() for _ in range(V)]
def recognizes(self, txt):
"""Returns True if the text is matched by the regular expression.
:param txt: the text
:returns: True if the text is matched by the regular expression;
False otherwise
"""
regex = self.regex
graph = self.graph
m = self.m
dfs = DirectedDFS(graph, 0)
pc = Bag()
for v in range(0, graph.V()):
if dfs.is_marked(v):
pc.add(v)
# Compute possible NFA states for txt[i+1]
for i in range(0, len(txt)):
if txt[i] == "*" or txt[i] == "|" or txt[i] == "(" or txt[i] == ")":
raise ValueError("text contains the metacharacter '{}'".format(
txt[i]))
match = Bag()
for v in pc:
if v == m:
continue
if regex[v] == txt[i] or regex[i] == ".":
match.add(v + 1)
dfs = DirectedDFS(graph, *match)
pc = Bag()
for v in range(0, graph.V()):
if dfs.is_marked(v):
pc.add(v)
# Optimization if no states reachable
if pc.size() == 0:
return False
for v in pc:
if v == m:
return True
return False
def edges(self):
edges = Bag()
for v in range(self._V):
for e in self._adj[v]:
edges.add(e)
return edges