55 lines
1.1 KiB
Rust
55 lines
1.1 KiB
Rust
#![feature(test)]
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extern crate test;
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use aoc2021::common::*;
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use std::iter;
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const DAY: usize = 6;
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const DAYS_PER_CHILD: usize = 6;
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const DAYS_UNTIL_FERTILE: usize = 2;
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type Parsed = Vec<usize>;
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fn parse_input(raw: &str) -> Parsed {
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parse_nums_comma(raw)
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}
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fn part1(parsed: &Parsed, generations: usize) -> usize {
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iter::successors(Some(parsed.to_owned()), |fish| {
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let fish = fish
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.into_iter()
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.flat_map(|n| match n {
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0 => vec![DAYS_PER_CHILD, DAYS_PER_CHILD + DAYS_UNTIL_FERTILE],
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&n => vec![n - 1],
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})
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.collect();
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Some(fish)
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})
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.take(generations + 1)
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.last()
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.unwrap()
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.len()
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}
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fn part2(parsed: &Parsed) -> usize {
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unimplemented!()
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}
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fn main() {
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let input = parse_input(&read_file(DAY));
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println!("Part 1: {}", part1(&input, 80));
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println!("Part 2: {}", part2(&input));
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use aoc2021::*;
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const TEST_INPUT: &str = "3,4,3,1,2";
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test!(part1(80) == 5934);
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test!(part2() == 0);
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bench!(part1(80) == 364461);
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bench!(part2() == 0);
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bench_input!(Vec::len => 0);
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}
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