2023 day 20.

This commit is contained in:
Mikael CAPELLE 2023-12-20 14:18:17 +01:00
parent 12891194bb
commit dda2be2505
5 changed files with 244 additions and 21 deletions

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@ -28,12 +28,12 @@ def accept(workflows: dict[str, Workflow], part: Part) -> bool:
while decision is None: while decision is None:
for check, target in workflows[workflow]: for check, target in workflows[workflow]:
ok = check is None passed = check is None
if check is not None: if check is not None:
category, sense, value = check category, sense, value = check
ok = OPERATORS[sense](part[category], value) passed = OPERATORS[sense](part[category], value)
if ok: if passed:
if target in workflows: if target in workflows:
workflow = target workflow = target
else: else:
@ -44,35 +44,42 @@ def accept(workflows: dict[str, Workflow], part: Part) -> bool:
def propagate(workflows: dict[str, Workflow], start: PartWithBounds) -> int: def propagate(workflows: dict[str, Workflow], start: PartWithBounds) -> int:
def _fmt(meta: PartWithBounds) -> str:
return "{" + ", ".join(f"{k}={v}" for k, v in meta.items()) + "}"
def transfer_or_accept( def transfer_or_accept(
target: str, meta: PartWithBounds, queue: list[tuple[PartWithBounds, str]] target: str, meta: PartWithBounds, queue: list[tuple[PartWithBounds, str]]
) -> int: ) -> int:
count = 0
if target in workflows: if target in workflows:
logging.info(f" transfer to {target}") logging.info(f" transfer to {target}")
queue.append((meta, target)) queue.append((meta, target))
return 0
elif target == "A": elif target == "A":
logging.info(" accepted") count = prod((high - low + 1) for low, high in meta.values())
return prod((high - low + 1) for low, high in meta.values()) logging.info(f" accepted ({count})")
else: else:
logging.info(" rejected") logging.info(" rejected")
return 0 return count
accepted = 0 accepted = 0
queue: list[tuple[PartWithBounds, str]] = [(start, "in")] queue: list[tuple[PartWithBounds, str]] = [(start, "in")]
n_iterations = 0
while queue: while queue:
n_iterations += 1
meta, workflow = queue.pop() meta, workflow = queue.pop()
logging.info(f"{workflow}: {meta}") logging.info(f"{workflow}: {_fmt(meta)}")
for check, target in workflows[workflow]: for check, target in workflows[workflow]:
if check is None: if check is None:
logging.info(" end-of-workflow")
accepted += transfer_or_accept(target, meta, queue) accepted += transfer_or_accept(target, meta, queue)
continue continue
category, sense, value = check category, sense, value = check
bounds, op = meta[category], OPERATORS[sense] bounds, op = meta[category], OPERATORS[sense]
logging.info(f" splitting {meta} into {category} {sense} {value}") logging.info(f" checking {_fmt(meta)} against {category} {sense} {value}")
if not op(bounds[0], value) and not op(bounds[1], value): if not op(bounds[0], value) and not op(bounds[1], value):
logging.info(" reject, always false") logging.info(" reject, always false")
@ -84,16 +91,16 @@ def propagate(workflows: dict[str, Workflow], start: PartWithBounds) -> int:
break break
meta2 = meta.copy() meta2 = meta.copy()
low, high = meta[category]
if sense == "<": if sense == "<":
meta2[category] = (meta[category][0], value - 1) meta[category], meta2[category] = (value, high), (low, value - 1)
meta[category] = (value, meta[category][1])
else: else:
meta2[category] = (value + 1, meta[category][1]) meta[category], meta2[category] = (low, value), (value + 1, high)
meta[category] = (meta[category][0], value) logging.info(f" split {_fmt(meta2)} ({target}), {_fmt(meta)}")
logging.info(f" split {meta2} ({target}), {meta}")
accepted += transfer_or_accept(target, meta2, queue) accepted += transfer_or_accept(target, meta2, queue)
logging.info(f"run took {n_iterations} iterations")
return accepted return accepted

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@ -1,13 +1,161 @@
import logging
import os
import sys import sys
from collections import defaultdict from collections import defaultdict
from dataclasses import dataclass from math import lcm
from typing import Literal, TypeAlias
VERBOSE = os.getenv("AOC_VERBOSE") == "True"
logging.basicConfig(level=logging.INFO if VERBOSE else logging.WARNING)
ModuleType: TypeAlias = Literal["broadcaster", "conjunction", "flip-flop"]
PulseType: TypeAlias = Literal["high", "low"]
modules: dict[str, tuple[ModuleType, list[str]]] = {}
lines = sys.stdin.read().splitlines() lines = sys.stdin.read().splitlines()
for line in lines:
name, outputs_s = line.split(" -> ")
outputs = outputs_s.split(", ")
if name == "broadcaster":
modules["broadcaster"] = ("broadcaster", outputs)
else:
modules[name[1:]] = (
"conjunction" if name.startswith("&") else "flip-flop",
outputs,
)
def process(
start: tuple[str, str, PulseType],
flip_flop_states: dict[str, Literal["on", "off"]],
conjunction_states: dict[str, dict[str, PulseType]],
) -> tuple[dict[PulseType, int], dict[str, dict[PulseType, int]]]:
pulses: list[tuple[str, str, PulseType]] = [start]
counts: dict[PulseType, int] = {"low": 0, "high": 0}
inputs: dict[str, dict[PulseType, int]] = defaultdict(lambda: {"low": 0, "high": 0})
logging.info("starting process... ")
while pulses:
input, name, pulse = pulses.pop(0)
logging.info(f"{input} -{pulse}-> {name}")
counts[pulse] += 1
inputs[name][pulse] += 1
if name not in modules:
continue
type, outputs = modules[name]
if type == "broadcaster":
...
elif type == "flip-flop":
if pulse == "high":
continue
if flip_flop_states[name] == "off":
flip_flop_states[name] = "on"
pulse = "high"
else:
flip_flop_states[name] = "off"
pulse = "low"
else:
conjunction_states[name][input] = pulse
if all(state == "high" for state in conjunction_states[name].values()):
pulse = "low"
else:
pulse = "high"
pulses.extend((name, output, pulse) for output in outputs)
return counts, inputs
with open("./day20.dot", "w") as fp:
fp.write("digraph G {\n")
fp.write("rx [shape=circle, color=red, style=filled];\n")
for name, (type, outputs) in modules.items():
if type == "conjunction":
shape = "diamond"
elif type == "flip-flop":
shape = "box"
else:
shape = "circle"
fp.write(f"{name} [shape={shape}];\n")
for name, (type, outputs) in modules.items():
for output in outputs:
fp.write(f"{name} -> {output};\n")
fp.write("}\n")
# part 1 # part 1
answer_1 = ... flip_flop_states: dict[str, Literal["on", "off"]] = {
name: "off" for name, (type, _) in modules.items() if type == "flip-flop"
}
conjunction_states: dict[str, dict[str, PulseType]] = {
name: {input: "low" for input, (_, outputs) in modules.items() if name in outputs}
for name, (type, _) in modules.items()
if type == "conjunction"
}
counts: dict[PulseType, int] = {"low": 0, "high": 0}
for _ in range(1000):
result, _ = process(
("button", "broadcaster", "low"), flip_flop_states, conjunction_states
)
for pulse in ("low", "high"):
counts[pulse] += result[pulse]
answer_1 = counts["low"] * counts["high"]
print(f"answer 1 is {answer_1}") print(f"answer 1 is {answer_1}")
# part 2 # part 2
answer_2 = ...
# reset states
for name in flip_flop_states:
flip_flop_states[name] = "off"
for name in conjunction_states:
for input in conjunction_states[name]:
conjunction_states[name][input] = "low"
# find the conjunction connected to rx
to_rx = [name for name, (_, outputs) in modules.items() if "rx" in outputs]
assert len(to_rx) == 1, "cannot handle multiple module inputs for rx"
assert (
modules[to_rx[0]][0] == "conjunction"
), "can only handle conjunction as input to rx"
to_rx_inputs = [name for name, (_, outputs) in modules.items() if to_rx[0] in outputs]
assert all(
modules[i][0] == "conjunction" and len(modules[i][1]) == 1 for i in to_rx_inputs
), "can only handle inversion as second-order inputs to rx"
count = 1
cycles: dict[str, int] = {}
second: dict[str, int] = {}
while len(second) != len(to_rx_inputs):
_, inputs = process(
("button", "broadcaster", "low"), flip_flop_states, conjunction_states
)
for node in to_rx_inputs:
if inputs[node]["low"] == 1:
if node not in cycles:
cycles[node] = count
elif node not in second:
second[node] = count
count += 1
assert all(
second[k] == cycles[k] * 2 for k in to_rx_inputs
), "cannot only handle cycles starting at the beginning"
answer_2 = lcm(*cycles.values())
print(f"answer 2 is {answer_2}") print(f"answer 2 is {answer_2}")

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@ -0,0 +1,58 @@
%cf -> tz
%kr -> xn, gq
%cp -> sq, bd
broadcaster -> vn, sj, tg, kn
%hc -> pm
%fd -> xn, mj
%qz -> xf
%vf -> mc, pm
%zm -> rz, pm
%cn -> bd, qz
%jj -> bp
%ks -> ff
%nb -> xn, ks
%bm -> pm, vf
&xn -> kc, jb, cb, tg, ks, tx
%lm -> rk
%dn -> bd, cn
%ft -> dn
%pn -> pm, ll
%rk -> bp, fs
%tz -> bp, gp
%mc -> jx
%fs -> kx
%jf -> bd, fm
%rz -> hc, pm
%tg -> cb, xn
&hf -> rx
%vp -> pn
&pm -> ll, mc, sj, vd, vp
%rn -> kc, xn
%vn -> bd, cp
&nd -> hf
%fm -> bd, gc
%ff -> xn, fd
&bp -> cf, fh, pc, kn, fs, gn, lm
&pc -> hf
%mj -> xn
%qg -> bd
%fh -> lm
%kc -> nb
%xf -> bd, jf
%gc -> qg, bd
&bd -> vn, sq, qz, ft, nd
%jb -> kr
%gp -> bp, rp
%gq -> xn, rn
%sj -> pm, bm
%rp -> bp, jj
%sq -> ft
%cb -> jb
&vd -> hf
%gn -> cf
%kx -> gn, bp
%ll -> zm
&tx -> hf
%jx -> md, pm
%md -> pm, vp
%kn -> fh, bp

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@ -0,0 +1,5 @@
broadcaster -> a, b, c
%a -> b
%b -> c
%c -> inv
&inv -> a

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@ -0,0 +1,5 @@
broadcaster -> a
%a -> inv, con
&inv -> b
%b -> con
&con -> output