python实现图:
邻接表表示:
a,b,c,d,e,f,g,h=range(8)
N=[[b,c,d,e,f],#a
[c,e],#b
[d],#c
[e],#d
[f],#e
[c,g,h],#f
[f,h],#g
[f,g]#h
]
N
邻接矩阵表示:
matrix = [[0, 1, 1, 1, 1, 1, 0, 0], # a
[0, 0, 1, 0, 1, 0, 0, 0], # b
[0, 0, 0, 1, 0, 0, 0, 0], # c
[0, 0, 0, 0, 1, 0, 0, 0], # d
[0, 0, 0, 0, 0, 1, 0, 0], # e
[0, 0, 1, 0, 0, 0, 1, 1], # f
[0, 0, 0, 0, 0, 1, 0, 1], # g
[0, 0, 0, 0, 0, 1, 1, 0]] # h
深度优先,广度优先:
#!/usr/bin/python
# -*- coding: utf-8 -*-
class Graph(object):
def __init__(self,*args,**kwargs):
self.node_neighbors = {}
self.visited = {}
def add_nodes(self,nodelist):
for node in nodelist:
self.add_node(node)
def add_node(self,node):
if not node in self.nodes():
self.node_neighbors[node] = []
def add_edge(self,edge):
u,v = edge
if(v not in self.node_neighbors[u]) and ( u not in self.node_neighbors[v]):
self.node_neighbors[u].append(v)
if(u!=v):
self.node_neighbors[v].append(u)
def nodes(self):
return self.node_neighbors.keys()
def depth_first_search(self,root=None):
order = []
def dfs(node):
self.visited[node] = True
order.append(node)
for n in self.node_neighbors[node]:
if not n in self.visited:
dfs(n)
if root:
dfs(root)
for node in self.nodes():
if not node in self.visited:
dfs(node)
return order
def breadth_first_search(self,root=None):
queue = []
order = []
def bfs():
while len(queue)> 0:
node = queue.pop(0)
self.visited[node] = True
for n in self.node_neighbors[node]:
if (not n in self.visited) and (not n in queue):
queue.append(n)
order.append(n)
if root:
queue.append(root)
order.append(root)
bfs()
for node in self.nodes():
if not node in self.visited:
queue.append(node)
order.append(node)
bfs()
return order
if __name__ == '__main__':
g = Graph()
g.add_nodes([i+1 for i in range(8)])
g.add_edge((1, 2))
g.add_edge((1, 3))
g.add_edge((2, 4))
g.add_edge((2, 5))
g.add_edge((4, 8))
g.add_edge((5, 8))
g.add_edge((3, 6))
g.add_edge((3, 7))
g.add_edge((6, 7))
print("nodes:", g.nodes())
order1 = g.breadth_first_search(1)
print('广度优先遍历:',order1)
order2 = g.depth_first_search(1)
print('深度优先遍历:',order2)
# print(g.node_neighbors)