请问在网络上哪里可以找到关于Bron-Kerbosch算法寻找完全子图的解释,或者能否在这里进行解释?
我知道它是在《算法457:查找无向图中所有团的算法》一书中发表的,但我找不到免费的资源来描述算法。
我不需要该算法的源代码,我需要的是它如何运作的解释。
请问在网络上哪里可以找到关于Bron-Kerbosch算法寻找完全子图的解释,或者能否在这里进行解释?
我知道它是在《算法457:查找无向图中所有团的算法》一书中发表的,但我找不到免费的资源来描述算法。
我不需要该算法的源代码,我需要的是它如何运作的解释。
尝试寻找拥有ACM学生账户的人,向他们获取论文副本,该论文可以在此处找到:http://portal.acm.org/citation.cfm?doid=362342.362367
我刚刚下载了它,只有两页,使用的是Algol 60编程语言实现!
这里有一个算法链接,我已经使用Java中的链表作为集合R、P、X进行了重写,并且它运行得非常好(根据该算法进行集合操作时,使用函数“retainAll”是一件好事)。
我建议您在重新编写算法时考虑优化问题。
我也在尝试理解Bron-Kerbosch算法,所以我用Python编写了自己的实现。它包括一个测试用例和一些注释。希望这可以帮到你。
class Node(object):
def __init__(self, name):
self.name = name
self.neighbors = []
def __repr__(self):
return self.name
A = Node('A')
B = Node('B')
C = Node('C')
D = Node('D')
E = Node('E')
A.neighbors = [B, C]
B.neighbors = [A, C]
C.neighbors = [A, B, D]
D.neighbors = [C, E]
E.neighbors = [D]
all_nodes = [A, B, C, D, E]
def find_cliques(potential_clique=[], remaining_nodes=[], skip_nodes=[], depth=0):
# To understand the flow better, uncomment this:
# print (' ' * depth), 'potential_clique:', potential_clique, 'remaining_nodes:', remaining_nodes, 'skip_nodes:', skip_nodes
if len(remaining_nodes) == 0 and len(skip_nodes) == 0:
print 'This is a clique:', potential_clique
return
for node in remaining_nodes:
# Try adding the node to the current potential_clique to see if we can make it work.
new_potential_clique = potential_clique + [node]
new_remaining_nodes = [n for n in remaining_nodes if n in node.neighbors]
new_skip_list = [n for n in skip_nodes if n in node.neighbors]
find_cliques(new_potential_clique, new_remaining_nodes, new_skip_list, depth + 1)
# We're done considering this node. If there was a way to form a clique with it, we
# already discovered its maximal clique in the recursive call above. So, go ahead
# and remove it from the list of remaining nodes and add it to the skip list.
remaining_nodes.remove(node)
skip_nodes.append(node)
find_cliques(remaining_nodes=all_nodes)
def bron(compsub, _not, candidates, graph, cliques):
if len(candidates) == 0 and len(_not) == 0:
cliques.append(tuple(compsub))
return
if len(candidates) == 0: return
sel = candidates[0]
candidates.remove(sel)
newCandidates = removeDisconnected(candidates, sel, graph)
newNot = removeDisconnected(_not, sel, graph)
compsub.append(sel)
bron(compsub, newNot, newCandidates, graph, cliques)
compsub.remove(sel)
_not.append(sel)
bron(compsub, _not, candidates, graph, cliques)
然后你调用这个函数:
graph = # 2x2 boolean matrix
cliques = []
bron([], [], graph, cliques)
变量cliques
将包含找到的团。
一旦你理解了这个,实现优化就很容易了。
如果有用的话,我找到了一个Java实现:http://joelib.cvs.sourceforge.net/joelib/joelib2/src/joelib2/algo/clique/BronKerbosch.java?view=markup
希望对你有帮助。