import numpy as np
from collections import deque

file = "inputs/day12.input"
lines = open(file, "rb").read().decode().split("\n")[:-1]
starts = []
ends = []
for line in lines:
    start, end = line.split("-")
    starts.append(start)
    ends.append(end)

nodes = set(starts + ends)
neighbours = {key: [] for key in nodes}

for idx, start in enumerate(starts):
    neighbours[start].append(ends[idx])
    neighbours[ends[idx]].append(start)


def find_way(node, way):
    if node == "end":
        way.append(node)
        ways.append(way)
        return
    adjacents = neighbours[node]
    if (
        len(adjacents) == 1
        and adjacents[0] == adjacents[0].lower()
        and adjacents[0] in way
    ):
        return
    way.append(node)
    for adjacent in adjacents:
        if adjacent == adjacent.lower() and adjacent in way:
            continue
        else:
            find_way(adjacent, way.copy())


ways = []
find_way("start", [])
print(neighbours)
print(ways)
print(len(ways))