AdventOfCode2023/src/day6.rs
2023-12-18 09:37:54 -05:00

80 lines
2.2 KiB
Rust

use aoc_runner_derive::{aoc, aoc_generator};
#[aoc_generator(day6, part1)]
fn parse(input: &str) -> Vec<Vec<i32>> {
let input: Vec<Vec<i32>> = input.split('\n') // Separate the Time and Distance lines
.map(|line| {
line[line.find(':').unwrap() + 1..] // Drop "Time:" and "Distance:"
.split_whitespace() // Split the numbers into their own elements.
.map(|num| num.parse::<i32>().expect("Couldn't parse number")) // Parse numbers into i32
.collect::<Vec<_>>()
}).collect::<Vec<_>>(); // collect into Vec
input
}
#[aoc(day6, part1)]
fn part1(input: &Vec<Vec<i32>>) -> i32 {
let mut valid_total = 1;
for round in 0..input.first().unwrap().len() {
let time = input[0][round];
let dist = input[1][round];
let mut valid = 0;
for remaining_time in 0..time {
if (time - remaining_time) * remaining_time > dist {
valid += 1;
}
}
valid_total *= valid;
}
valid_total
}
#[aoc_generator(day6, part2)]
fn parse_part2(input: &str) -> Vec<i64> {
let input: Vec<i64> = input.split('\n') // Separate the Time and Distance lines
.map(|line| {
line[line.find(':').unwrap() + 1..] // Drop "Time:" and "Distance:"
.split_whitespace() // Split the numbers into their own elements
.flat_map(|s| s.chars()).collect::<String>() // Combine the strings into a single one
.parse::<i64>().expect("Couldn't parse number") // Parse numbers into i32
}).collect(); // Collect into Vec
input
}
#[aoc(day6, part2)]
fn part2(input: &Vec<i64>) -> i32 {
let time = input[0];
let dist = input[1];
let mut valid = 0;
for remaining_time in 0..time {
if (time - remaining_time) * remaining_time > dist {
valid += 1;
}
}
valid
}
#[cfg(test)]
mod tests {
use super::*;
const EX: &str = r"Time: 7 15 30
Distance: 9 40 200";
#[test]
fn part1_example() {
assert_eq!(part1(&parse(EX)), 288);
}
#[test]
fn part2_example() {
assert_eq!(part2(&parse_part2(EX)), 71503);
}
}