I used the solution to this problem to print all root to leaves path for a n-ary tree I have. Unfortunately, I suspect, there is a cycle in one of the branch of the tree due to which the program breaches the maximum recursion limit.
A
/ \
B C
| /\
D E F
|
A (back to root)
D again goes back to A
Please tell me how should I handle the cycle detection in the below program.
def paths(tree):
#Helper function
#receives a tree and
#returns all paths that have this node as root and all other paths
if tree is the empty tree:
return ([], [])
else: #tree is a node
root = tree.value
rooted_paths = [[root]]
unrooted_paths = []
for subtree in tree.children:
(useable, unueseable) = paths(subtree)
for path in useable:
unrooted_paths.append(path)
rooted_paths.append([root]+path)
for path in unuseable:
unrooted_paths.append(path)
return (rooted_paths, unrooted_paths)
def the_function_you_use_in_the_end(tree):
a,b = paths(tree)
return a+b
p.s: I tried using visited nodes logic for detection, but that is not very helpful as a node can be legitimately visited multiple numbers of time:
for Example: A C A C E A C F
C is visited multiple numbers of times
