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Solve 13

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This commit is contained in:
Lars Martens 2024-12-13 10:36:38 +01:00
parent 67610d0808
commit 9c97e04062
1 changed files with 30 additions and 61 deletions
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89
src/bin/13.rs
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@ -1,8 +1,8 @@
use aoc::*;
use cached::proc_macro::cached;
use glam::U64Vec2;
use glam::I64Vec2;
use itertools::Itertools;
use regex::Regex;
use std::sync::LazyLock;
const INPUT: &str = include_str!("../../input/13");
@ -12,18 +12,15 @@ fn main() {
println!("Part 2: {}", part2(INPUT));
}
fn part1(input: &str) -> usize {
parse(input)
.into_iter()
.map(ClawMachine::tokens_to_win)
.sum()
fn part1(input: &str) -> i64 {
parse(input).into_iter().map(|c| c.tokens_to_win(100)).sum()
}
fn part2(input: &str) -> usize {
fn part2(input: &str) -> i64 {
parse(input)
.into_iter()
.map(ClawMachine::fix_conversion_error)
.map(ClawMachine::tokens_to_win2)
.map(|c| c.tokens_to_win(i64::MAX))
.sum()
}
@ -33,73 +30,45 @@ fn parse(input: &str) -> Vec<ClawMachine> {
#[derive(Debug, Hash, PartialEq, Eq, Clone, Copy)]
struct ClawMachine {
a: U64Vec2,
b: U64Vec2,
prize: U64Vec2,
a: I64Vec2,
b: I64Vec2,
prize: I64Vec2,
}
impl ClawMachine {
fn fix_conversion_error(self) -> Self {
Self {
prize: U64Vec2::new(self.prize.x + 10000000000000, self.prize.y + 10000000000000),
prize: self.prize + I64Vec2::splat(10000000000000),
..self
}
}
fn tokens_to_win(self) -> usize {
tokens_to_win(self, 0, 0, U64Vec2::ZERO)
fn tokens_to_win(self, limit: i64) -> i64 {
let b = (self.a.x * self.prize.y - self.a.y * self.prize.x)
/ (self.a.x * self.b.y - self.a.y * self.b.x);
let a = (self.prize.x - self.b.x * b) / self.a.x;
if a > limit || b > limit {
return 0;
}
fn tokens_to_win2(self) -> usize {
tokens_to_win2(self, 0, 0, U64Vec2::ZERO)
if (a * self.a + b * self.b) == self.prize {
a * 3 + b
} else {
0
}
}
fn parse(input: &str) -> Self {
let re =
Regex::new(r"X\+(\d+), Y\+(\d+)\n.*X\+(\d+), Y\+(\d+)\n.*X=(\d+), Y=(\d+)").unwrap();
let captures = re.captures(input).unwrap();
let captures = REGEX.captures(input).unwrap();
Self {
a: U64Vec2::new(captures[1].parse().unwrap(), captures[2].parse().unwrap()),
b: U64Vec2::new(captures[3].parse().unwrap(), captures[4].parse().unwrap()),
prize: U64Vec2::new(captures[5].parse().unwrap(), captures[6].parse().unwrap()),
a: I64Vec2::new(captures[1].parse().unwrap(), captures[2].parse().unwrap()),
b: I64Vec2::new(captures[3].parse().unwrap(), captures[4].parse().unwrap()),
prize: I64Vec2::new(captures[5].parse().unwrap(), captures[6].parse().unwrap()),
}
}
}
#[cached]
fn tokens_to_win(machine: ClawMachine, pressed_a: usize, pressed_b: usize, pos: U64Vec2) -> usize {
if pressed_a > 100 || pressed_b > 100 {
0
} else if pos == machine.prize {
pressed_a * 3 + pressed_b
} else if pos.x > machine.prize.x || pos.y > machine.prize.y {
0
} else {
let a = tokens_to_win(machine, pressed_a + 1, pressed_b, pos + machine.a);
let b = tokens_to_win(machine, pressed_a, pressed_b + 1, pos + machine.b);
match (a, b) {
(0, 0) => 0,
(a, 0) => a,
(0, b) => b,
(a, b) => a.min(b),
}
}
}
#[cached]
fn tokens_to_win2(machine: ClawMachine, pressed_a: usize, pressed_b: usize, pos: U64Vec2) -> usize {
if pos == machine.prize {
pressed_a * 3 + pressed_b
} else if pos.x > machine.prize.x || pos.y > machine.prize.y {
0
} else {
let a = tokens_to_win(machine, pressed_a + 1, pressed_b, pos + machine.a);
let b = tokens_to_win(machine, pressed_a, pressed_b + 1, pos + machine.b);
match (a, b) {
(0, 0) => 0,
(a, 0) => a,
(0, b) => b,
(a, b) => a.min(b),
}
}
}
static REGEX: LazyLock<Regex> = LazyLock::new(|| {
Regex::new(r"X\+(\d+), Y\+(\d+)\n.*X\+(\d+), Y\+(\d+)\n.*X=(\d+), Y=(\d+)").unwrap()
});