我想在 Python 中实现禁忌搜索来解决与图形相关的问题(查找树、着色问题和那种东西)。我已经用 Python 编写了基本代码,这是我第一次编写类似的代码。我知道算法是如何工作的(理论上),但我在实现它时遇到了一些麻烦。
生成随机解决方案以便我可以启动算法的最佳方法是什么?我想从初始图生成一棵随机树:
graph = { "a" : ["c"],
"b" : ["c", "e"],
"c" : ["a", "b", "d", "e"],
"d" : ["c"],
"e" : ["c", "b"],
"f" : []
}
我正在使用这些函数来查看边缘和孤立节点:
def generate_edges(graph):
edges = []
for node in graph:
for neighbour in graph[node]:
edges.append((node, neighbour))
return edges
print(generate_edges(graph))
def find_isolated_nodes(graph):
""" returns a list of isolated nodes. """
isolated = []
for node in graph:
if not graph[node]:
isolated += node
return isolated
print(find_isolated_nodes(graph))
而这个找到路径:
def find_all_paths(self, start_vertex, end_vertex, path=[]):
""" find all paths from start_vertex to
end_vertex in graph """
graph = self.__graph_dict
path = path + [start_vertex]
if start_vertex == end_vertex:
return [path]
if start_vertex not in graph:
return []
paths = []
for vertex in graph[start_vertex]:
if vertex not in path:
extended_paths = self.find_all_paths(vertex,
end_vertex,
path)
for p in extended_paths:
paths.append(p)
return paths
我需要的是找到一棵树作为随机解决方案,这样我就可以更改它,直到我拥有的图表中最大的可能。
最好的方法是什么?谢谢你。