Aaron Scott a écrit :
I have a list of nodes, and I need to find a path from one node to
another. The nodes each have a list of nodes they are connected to,
set up like this:
class Node(object):
def __init__(self, connectedNodes):
self.connectedNodes = connectedNodes
nodes = {
1: Node([4]),
2: Node([3]),
3: Node([2, 4, 5]),
4: Node([1, 6, 3]),
5: Node([3, 7]),
6: Node([4, 9]),
7: Node([5, 8]),
8: Node([7, 9]),
9: Node([6, 8])
}
I made a quick brute-force pathfinder to solve it (in this case, a
path from node 1 to node 9). Here it is:
class PathFind(object):
def __init__(self, source, destination):
self.source = source
self.destination = destination
self.solved = []
def Search(self):
self.PathFind([self.source])
>
if self.solved:
print "Solutions: "
for i in self.solved:
print "\t" + str(i)
print "\t%s" % i
else:
print "Couldn't solve."
def PathFind(self, trail):
location = trail[-1]
if location == self.destination:
self.solved.append(trail)
I think you want
self.solved.append(trail[:])
Hint : Python doesn't use "pass by value".
> The problem is the array trail[], which seems to survive from instance
to instance of PathFind(). I thought that by calling self.PathFind
(trail[:]), I was creating a new copy of trail[],
Yes. But on the 'not solved' branch, you do mutate trail !-)
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