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import networkx as nx | |
import os | |
import numpy as np | |
import time | |
import random | |
def mvc(graph): | |
cost = {u:1 for u in range(graph.number_of_nodes())} | |
for u,v in graph.edges: | |
min_cost = min(cost[u], cost[v]) | |
cost[u] -= min_cost | |
cost[v] -= min_cost | |
return {u for u,v in cost.iteritems() if v ==0} | |
# or use this | |
def my_mvc(graph): | |
# We are going to modify the graph | |
graph = graph.copy() | |
vc = set() | |
while graph.number_of_edges() > 0: | |
sorted_edges = sorted(graph.edges, key = lambda (x,y): - graph.degree(x) - graph.degree(y)) | |
u,v = sorted_edges[0] | |
vc.add(u) | |
vc.add(v) | |
graph.remove_node(u) | |
graph.remove_node(v) | |
return vc | |
vc = [] | |
data_dir = "/data/qpbo/buaa/mc/data/" | |
for _,subdirs,_ in os.walk(data_dir): | |
for subdir in subdirs: | |
for _,_,filenames in os.walk(os.path.join(data_dir, subdir)): | |
for file in filenames: | |
filepath = os.path.join(data_dir, subdir, file) | |
content = open(filepath) | |
n,e = map(int, content.readline().split()[2:]) | |
edges = [] | |
for line in content: | |
edges.append(map(lambda x:int(x)-1, line.split()[1:])) | |
graph = nx.Graph() | |
graph.add_edges_from(edges) | |
print filepath, x | |
x = len(mvc(graph)) | |
vc.append(x) | |
print "mean vc size:{}".format(np.mean(vc)) |
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