Zeggen dat ik knooppunten in de onderstaande manier aangesloten, hoe kom ik bij het aantal paden die er bestaan tussen bepaalde punten, en het pad informatie?
1,2 //node 1 and 2 are connected
2,3
2,5
4,2
5,11
11,12
6,7
5,6
3,6
6,8
8,10
8,9
Vind de paden 1-7:
Antwoord: 2 paden gevonden en ze zijn
1,2,3,6,7
1,2,5,6,7
implementatie gevonden hier is leuk ga ik gebruik maken van dezelfde
Hier is het fragment uit de bovenstaande link in python
# a sample graph
graph = {'A': ['B', 'C','E'],
'B': ['A','C', 'D'],
'C': ['D'],
'D': ['C'],
'E': ['F','D'],
'F': ['C']}
class MyQUEUE: # just an implementation of a queue
def __init__(self):
self.holder = []
def enqueue(self,val):
self.holder.append(val)
def dequeue(self):
val = None
try:
val = self.holder[0]
if len(self.holder) == 1:
self.holder = []
else:
self.holder = self.holder[1:]
except:
pass
return val
def IsEmpty(self):
result = False
if len(self.holder) == 0:
result = True
return result
path_queue = MyQUEUE() # now we make a queue
def BFS(graph,start,end,q):
temp_path = [start]
q.enqueue(temp_path)
while q.IsEmpty() == False:
tmp_path = q.dequeue()
last_node = tmp_path[len(tmp_path)-1]
print tmp_path
if last_node == end:
print VALID_PATH : ,tmp_path
for link_node in graph[last_node]:
if link_node not in tmp_path:
#new_path = []
new_path = tmp_path + [link_node]
q.enqueue(new_path)
BFS(graph,A,D,path_queue)
-------------results-------------------
['A']
['A', 'B']
['A', 'C']
['A', 'E']
['A', 'B', 'C']
['A', 'B', 'D']
VALID_PATH : ['A', 'B', 'D']
['A', 'C', 'D']
VALID_PATH : ['A', 'C', 'D']
['A', 'E', 'F']
['A', 'E', 'D']
VALID_PATH : ['A', 'E', 'D']
['A', 'B', 'C', 'D']
VALID_PATH : ['A', 'B', 'C', 'D']
['A', 'E', 'F', 'C']
['A', 'E', 'F', 'C', 'D']
VALID_PATH : ['A', 'E', 'F', 'C', 'D']
