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Day 8 - cleanup

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This commit is contained in:
Stefan Harmuth 2023-12-08 07:14:41 +01:00
parent b3bddd521f
commit bb4fde783f
1 changed files with 19 additions and 29 deletions
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48
day08.py
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@ -1,9 +1,23 @@
import math import math
from collections import defaultdict
from tools.aoc import AOCDay from tools.aoc import AOCDay
from typing import Any from typing import Any
def get_steps_to_z(inst: str, nodes: dict, from_node: str) -> int:
i_len = len(inst)
cur_step = 0
cur_node = from_node
while not cur_node.endswith("Z"):
if inst[cur_step % i_len] == "L":
cur_node = nodes[cur_node][0]
else:
cur_node = nodes[cur_node][1]
cur_step += 1
return cur_step
class Day(AOCDay): class Day(AOCDay):
inputs = [ inputs = [
[ [
@ -21,44 +35,20 @@ class Day(AOCDay):
inst = self.getInput()[0] inst = self.getInput()[0]
nodes = {} nodes = {}
for line in self.getInput()[2:]: for line in self.getInput()[2:]:
node, pathhs = line.split(" = ") node, paths = line.split(" = ")
pl, pr = pathhs.split(", ") pl, pr = paths.split(", ")
nodes[node] = (pl[1:], pr[:-1]) nodes[node] = (pl[1:], pr[:-1])
return inst, nodes return inst, nodes
def part1(self) -> Any: def part1(self) -> Any:
inst, nodes = self.parse_input() inst, nodes = self.parse_input()
cur_node = "AAA" return get_steps_to_z(inst, nodes, "AAA")
cur_step = 0
while cur_node != "ZZZ":
dir = inst[cur_step % len(inst)]
if dir == "L":
cur_node = nodes[cur_node][0]
else:
cur_node = nodes[cur_node][1]
cur_step += 1
return cur_step
def part2(self) -> Any: def part2(self) -> Any:
inst, nodes = self.parse_input() inst, nodes = self.parse_input()
i_len = len(inst)
check_nodes = [x for x in nodes if x.endswith("A")] check_nodes = [x for x in nodes if x.endswith("A")]
z_steps = [] z_steps = [get_steps_to_z(inst, nodes, x) for x in check_nodes]
for node in check_nodes:
cur_step = 0
cur_node = node
while not cur_node.endswith("Z"):
if inst[cur_step % i_len] == "L":
cur_node = nodes[cur_node][0]
else:
cur_node = nodes[cur_node][1]
cur_step += 1
z_steps.append(cur_step)
return math.lcm(*z_steps) return math.lcm(*z_steps)