def __init__(self, vertices):
self._st = BinarySearchST() # string -> index
# built symbol table to translate strings into indices
for i in range(len(vertices)):
self._st.put(vertices[i], i)
# built array to translate from indices to strings
self._keys = [None] * self._st.size() # index -> string
for name in self._st.keys():
self._keys[self._st.get(name)] = name
# initialise graph
self._graph = Graph(self._st.size()) # the underlying graph
def __init__(self, filename, delimiter):
"""Initializes a graph from a file using the specified delimiter. Each
line in the file contains the name of a vertex, followed by a list of
the names of the vertices adjacent to that vertex, separated by the
delimiter.
:param filename: the name of the file
:param delimiter: the delimiter between fields
"""
self._st = BinarySearchST() # string -> index
# First pass builds the index by reading strings to associate
# distinct strings with an index
stream = InStream(filename)
while not stream.isEmpty():
a = stream.readLine().split(delimiter)
for i in range(len(a)):
if not self._st.contains(a[i]):
self._st.put(a[i], self._st.size())
stdio.writef("Done reading %s\n", filename)
# inverted index to get keys in an array
self._keys = [None] * self._st.size() # index -> string
for name in self._st.keys():
self._keys[self._st.get(name)] = name
# second pass builds the graph by connecting first vertex on each
# line to all others
self._graph = Graph(self._st.size()) # the underlying graph
stream = InStream(filename)
while stream.hasNextLine():
a = stream.readLine().split(delimiter)
v = self._st.get(a[0])
for i in range(1, len(a)):
w = self._st.get(a[i])
self._graph.add_edge(v, w)