adventofcode2021/12-1.py

50 lines
1.2 KiB
Python
Executable file

#!/usr/bin/env python
class Map:
def __init__(self, input):
self.neighbours = {}
self.paths = -1
def connect(self, cave1, cave2):
n1 = self.neighbours.get(cave1, [])
n2 = self.neighbours.get(cave2, [])
if cave2 not in n1:
n1.append(cave2)
if cave1 not in n2:
n2.append(cave1)
self.neighbours[cave1] = n1
self.neighbours[cave2] = n2
def visit(self, cave, path):
if cave == 'end':
self.paths += 1
else:
for n in self.neighbours[cave]:
if n.casefold() not in path:
self.visit(n, path + [cave])
def count_paths(self):
if self.paths >= 0:
return self.paths
self.paths = 0
self.visit('start', [])
return self.paths
def __str__(self):
s = f"<{self.__class__.__name__} ({self.paths}):\n"
for cave, neighbours in self.neighbours.items():
s += f"{cave} -> {neighbours}\n"
s += ">"
return s
map = Map(input)
input = [list(line.split("-")) for line in open('12.input').readlines()]
for conn in input:
map.connect(conn[0].strip(), conn[1].strip())
print(map.count_paths())