def read_graph_from_file(filename):
'''Parse edges from the file and load them into a graph object.'''
edges = read_edges_from_file(filename)
g = Graph()
for v, u in edges:
g.add_edge(v, u)
return g
def read_weighted_undirected_graph(filename):
g = Graph()
with open(filename) as f:
for line in f:
try:
v1, v2, w = line.split()
g.add_edge(v1, v2, {'weight': int(w)})
except:
pass
return g
def read_weighted_undirected_graph(filename):
"""A helper to read the edges of a graph described in the file
into a graph object."""
g = Graph()
with open(filename) as f:
for line in f:
try:
v1, v2, w = line.split()
g.add_edge(v1, v2, {'weight': int(w)})
except:
pass
return g
'''Use Prim's algorithm to compute the minimum spanning tree of the weighted undirected graph
described by the contents of the file named filename.'''
tree_edges = []
# TODO compute the edges of a minimum spanning tree
write_tree_edges_to_file(tree_edges, filename + '.mst')
if __name__ == '__main__':
#读取信息
g = Graph()
with open("5000 input") as f:
for line in f:
try:
v1, v2, w = line.split()
g.add_edge(v1, v2, {'weight': int(w)})
except:
pass
node_sets = initialize_disjoint_set(g.get_nodes())
node_count = len(node_sets)
#edges = [(g.attributes_of(v, u)['weight'], v, u) for u, v in g.get_edges()]
#edges.sort()
tree_edges = []
#查看读取信息
#print("node_sets is: ",node_sets)
#print("node_count is: ",node_count)
#print("edges is: ",edges)
#put all the G's node in the queue
queue = list(node_sets.keys())