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make more stupid assumptions

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kageru 2022-12-20 00:48:11 +01:00
parent ea4c15668f
commit 15b46e1975
Signed by: kageru
GPG Key ID: 8282A2BEA4ADA3D2
1 changed files with 27 additions and 18 deletions
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2022/src/bin/day19.rs
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@ -11,6 +11,7 @@ type Parsed = Vec<Blueprint>;
#[derive(Copy, Clone, PartialEq, Eq, Debug, Default)]
struct Factory {
minute: u32,
waited: u32,
ore: u32,
ore_robot: u32,
clay: u32,
@ -29,6 +30,7 @@ impl Factory {
obsidian: self.obsidian + self.obsidian_robot,
geode: self.geode + self.geode_robot,
minute: self.minute + 1,
waited: self.waited + 1,
..self
}
}
@ -90,47 +92,54 @@ fn parse_input(raw: &str) -> Parsed {
}
fn part1(parsed: &Parsed) -> u32 {
parsed.iter().map(|blueprint| max_geodes(Factory { ore_robot: 1, ..Default::default() }, blueprint, 24) * blueprint.number).sum()
parsed.iter().map(|blueprint| max_geodes(Factory { ore_robot: 1, ..Default::default() }, blueprint, 3, 24) * blueprint.number).sum()
}
fn part2(parsed: &Parsed) -> u32 {
parsed.iter().take(3).map(|blueprint| max_geodes(Factory { ore_robot: 1, ..Default::default() }, blueprint, 32)).product()
parsed.iter().take(3).map(|blueprint| max_geodes(Factory { ore_robot: 1, ..Default::default() }, blueprint, 4, 32)).product()
}
fn max_geodes(factory: Factory, bp: &Blueprint, limit: u32) -> u32 {
fn max_geodes(factory: Factory, bp: &Blueprint, wait_limit: u32, limit: u32) -> u32 {
if factory.minute == limit {
return factory.geode;
}
if factory.can_afford(&bp.geode_robot) {
return max_geodes(Factory { geode_robot: factory.geode_robot + 1, ..factory.pass_minute() } - bp.geode_robot, bp, limit);
return max_geodes(
Factory { geode_robot: factory.geode_robot + 1, waited: 0, ..factory.pass_minute() } - bp.geode_robot,
bp,
wait_limit,
limit,
);
}
// This assumption holds for my input but not the test input.
// Not entirely fair, but good enough until I figure out a better way.
// This assumption (“if we can build an obsidian robot, we should”) holds for my input but not the test input.
// Not entirely fair, but good enough until (or if at all) I figure out a better way.
if factory.obsidian_robot < bp.geode_robot.obsidian && factory.can_afford(&bp.obsidian_robot) {
return max_geodes(Factory { obsidian_robot: factory.obsidian_robot + 1, ..factory.pass_minute() } - bp.obsidian_robot, bp, limit);
return max_geodes(
Factory { obsidian_robot: factory.obsidian_robot + 1, waited: 0, ..factory.pass_minute() } - bp.obsidian_robot,
bp,
wait_limit,
limit,
);
}
let mut outcomes = Vec::with_capacity(3);
if factory.ore_robot < bp.max_ore && factory.can_afford(&bp.ore_robot) {
outcomes.push(Factory { ore_robot: factory.ore_robot + 1, ..factory.pass_minute() } - bp.ore_robot);
outcomes.push(Factory { ore_robot: factory.ore_robot + 1, waited: 0, ..factory.pass_minute() } - bp.ore_robot);
}
if factory.clay_robot < bp.obsidian_robot.clay && factory.can_afford(&bp.clay_robot) {
outcomes.push(Factory { clay_robot: factory.clay_robot + 1, ..factory.pass_minute() } - bp.clay_robot);
outcomes.push(Factory { clay_robot: factory.clay_robot + 1, waited: 0, ..factory.pass_minute() } - bp.clay_robot);
}
// There seem to be steps where doing nothing is the right choice even if we could produce
// another robot according to the rules above. If I could eliminate this, the number of tested
// lines is reduce by a factor of ~1_000_000
outcomes.push(factory.pass_minute());
outcomes.into_iter().map(|f| max_geodes(f, bp, limit)).max().unwrap()
if outcomes.is_empty() || factory.waited < wait_limit {
outcomes.push(factory.pass_minute());
}
outcomes.into_iter().take(2).map(|f| max_geodes(f, bp, wait_limit, limit)).max().unwrap()
}
boilerplate! {
TEST_INPUT == "\
Blueprint 1: Each ore robot costs 4 ore. Each clay robot costs 2 ore. Each obsidian robot costs 3 ore and 14 clay. Each geode robot costs 2 ore and 7 obsidian.
Blueprint 2: Each ore robot costs 2 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 8 clay. Each geode robot costs 3 ore and 12 obsidian.",
tests: {
part1: { TEST_INPUT => 33 },
// part2: { TEST_INPUT => 3472 },
},
tests: { part1: { TEST_INPUT => 33 } },
bench1 == 1150,
bench2 == 37367,
bench_parse: Vec::len => 30,