Created
December 12, 2021 16:36
-
-
Save andrealaforgia/bf268fe1390a37259dd63b512c03eb43 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
class Node: | |
def __init__(self, name): | |
self.adjacent_nodes = [] | |
self.name = name | |
self.traversed = 0 | |
def add_adjacent_node(self, adjacent_node): | |
self.adjacent_nodes.append(adjacent_node) | |
def is_small_cave(self): | |
return self.name[0].islower() | |
def load_nodes(lines): | |
node_dict = {} | |
start_node = None | |
end_node = None | |
for line in lines: | |
cave_names = line.split("-") | |
node1 = node_dict.get(cave_names[0]) or Node(cave_names[0]) | |
node2 = node_dict.get(cave_names[1]) or Node(cave_names[1]) | |
node1.add_adjacent_node(node2) | |
node2.add_adjacent_node(node1) | |
node_dict[cave_names[0]] = node1 | |
node_dict[cave_names[1]] = node2 | |
if node1.name == "start": | |
start_node = node1 | |
elif node1.name == "end": | |
end_node = node1 | |
if node2.name == "start": | |
start_node = node2 | |
elif node2.name == "end": | |
end_node = node2 | |
return start_node, end_node | |
def find_paths(current_node, path, paths): | |
if current_node == end_node: | |
paths.append(path) | |
return | |
reachable_nodes = [node for node in current_node.adjacent_nodes if node.traversed == 0] | |
if len(reachable_nodes) == 0: | |
return | |
for node in reachable_nodes: | |
new_path = path.copy() | |
new_path.append(node) | |
if node.is_small_cave(): | |
node.traversed = 1 | |
find_paths(node, new_path, paths) | |
node.traversed = 0 | |
def print_path(path): | |
s = "" | |
for node in path: | |
s += node.name | |
if node.name != "end": | |
s += "," | |
print(s) | |
if __name__ == "__main__": | |
with open("input3.txt") as file: | |
lines = [line.strip() for line in file.readlines()] | |
start_node, end_node = load_nodes(lines) | |
start_node.traversed = 1 | |
paths = [] | |
find_paths(start_node, [start_node], paths) | |
for path in paths: | |
print_path(path) | |
print(len(paths)) | |
assert len(paths) == 3802 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment