advent-of-code/2022/day16.py

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2022-12-16 08:21:54 +00:00
# -*- encoding: utf-8 -*-
import itertools
import re
import sys
from docplex.mp.model import Model
lines = sys.stdin.read().splitlines()
pipes: dict[str, tuple[int, list[str]]] = {}
for line in lines:
r = re.match(
R"Valve ([A-Z]+) has flow rate=([0-9]+); tunnels? leads? to valves? (.+)",
line,
).groups()
pipes[r[0]] = (int(r[1]), r[2].split(", "))
start_pipe = "AA"
max_time = 30
#
max_time = 26
ee = [0, 1]
m = Model()
present_at = m.binary_var_dict(
(e, t, pipe) for e, t, pipe in itertools.product(ee, range(max_time), pipes)
)
open_at = m.binary_var_dict(
(e, t, pipe) for e, t, pipe in itertools.product(ee, range(max_time), pipes)
)
for e in ee:
m.add_constraint(present_at[e, 0, start_pipe] == 1)
for e, pipe in itertools.product(ee, pipes):
m.add_constraint(open_at[e, 0, pipe] == 0)
for e, t in itertools.product(ee, range(max_time)):
m.add_constraint(m.sum(present_at[e, t, pipe] for pipe in pipes) == 1)
for e, t, pipe in itertools.product(ee, range(1, max_time), pipes):
m.add_constraint(
present_at[e, t, pipe]
<= present_at[e, t - 1, pipe]
+ m.sum(present_at[e, t - 1, pipe2] for pipe2 in pipes[pipe][1])
)
for pipe2 in pipes:
if pipe2 != pipe:
m.add_constraint(present_at[e, t, pipe] <= 1 - open_at[e, t - 1, pipe2])
for e, t, pipe in itertools.product(ee, range(1, max_time), pipes):
m.add_constraint(open_at[e, t, pipe] <= present_at[e, t, pipe])
# keeps flowing
flowing_at = m.binary_var_dict(
(t, pipe) for t, pipe in itertools.product(range(max_time), pipes)
)
for t, pipe in itertools.product(range(max_time), pipes):
m.add_constraint(
flowing_at[t, pipe]
== m.sum(open_at[e, t2, pipe] for e, t2 in itertools.product(ee, range(0, t)))
)
# objective
m.set_objective(
"max",
m.sum(
flowing_at[t, pipe] * pipes[pipe][0]
for t, pipe in itertools.product(range(max_time), pipes)
),
)
m.log_output = True
s = m.solve()
print(s.get_objective_value())
# for t in range(max_time):
# present = {
# e: [pipe for pipe in pipes if s.get_value(present_at[e, t, pipe]) > 1e-6]
# for e in ee
# }
# opent = {
# e: [pipe for pipe in pipes if s.get_value(open_at[e, t, pipe]) > 1e-6]
# for e in ee
# }
# flowing = [
# pipe
# for pipe in pipes
# if any(s.get_value(flowing_at[e, t, pipe]) > 1e-6 for e in ee)
# ]
# p = [present[e][0] for e in ee]
# o = [opent[e][0] if opent[e] else "-" for e in ee]
# print(f"t={t}, at={p}, open={o}, flowing={flowing}")