def __init__(self, data, part="a"):
grid = ZGrid(data, on=".", off="#")
if part == "b":
[z0] = [z for z, v in grid.items() if v == "@"]
pos = ("@0", "@1", "@2", "@3")
for dz in [0, -1j, 1, 1j, -1]:
grid[z0 + dz] = grid.off
for p, dz in zip(pos, [-1 - 1j, 1 - 1j, 1 + 1j, -1 + 1j]):
grid[z0 + dz] = p
else:
pos = ("@", )
graph = grid.graph(extra=frozenset(string.ascii_letters).union(pos))
self.all_keys = {k for k in graph.extra if k in string.ascii_lowercase}
# map of the other keys that must be acquired before each key is acquired
self.obstructions = {k: set() for k in self.all_keys}
# precached distances between points of interest
self.kdist = {}
for k0 in self.all_keys:
for p in pos:
try:
path = nx.shortest_path(graph, graph.extra[p],
graph.extra[k0])
except nx.NetworkXNoPath:
pass
else:
break
else:
raise Exception
self.kdist[k0, p] = self.kdist[p, k0] = len(path) - 1
assert path[0] == graph.extra[p]
assert path[-1] == graph.extra[k0]
for p in path[1:-1]:
if p in graph.extra.values():
k1 = grid[p].lower()
self.obstructions[k0].add(k1)
for k1, k2 in combinations(self.all_keys, 2):
z1 = graph.extra[k1]
z2 = graph.extra[k2]
try:
d = nx.shortest_path_length(graph, z1, z2)
except nx.NetworkXNoPath:
continue
self.kdist[k1, k2] = self.kdist[k2, k1] = d
state0 = pos, frozenset()
AStar.__init__(self, state0, target=None)
"""
--- Day 24: Air Duct Spelunking ---
https://adventofcode.com/2016/day/24
"""
from aoc_wim.zgrid import ZGrid
from itertools import combinations
from itertools import permutations
import networkx as nx
from aocd import data
grid = ZGrid(data, on=".", off="#")
graph = grid.graph(extra="0123456789")
distances = {}
for a, b in combinations(graph.extra, 2):
d = nx.shortest_path_length(graph, graph.extra[a], graph.extra[b])
distances[a, b] = distances[b, a] = d
def shortest_path(part="a"):
paths = {}
for nodes in permutations(graph.extra.keys() - {"0"}):
path = "0" + "".join(nodes)
if part == "b":
path += "0"
paths[path] = sum(distances[a, b] for a, b in zip(path, path[1:]))
return min(paths.values())
print("part a:", shortest_path(part="a"))
print("part b:", shortest_path(part="b"))
"""
--- Day 9: Smoke Basin ---
https://adventofcode.com/2021/day/9
"""
from aocd import data
import networkx as nx
from aoc_wim.zgrid import ZGrid
g = ZGrid(data)
bs = sorted(nx.connected_components(g.graph(extra="012345678")), key=len)
print("part a:", sum(min([1 + int(g[z]) for z in b]) for b in bs))
print("part b:", len(bs[-1]) * len(bs[-2]) * len(bs[-3]))