72 lines
1.6 KiB
Rust
72 lines
1.6 KiB
Rust
#![feature(test)]
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extern crate test;
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use aoc2023::{boilerplate, common::*};
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use itertools::Itertools;
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const DAY: usize = 11;
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type I = usize;
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type Parsed = (Vec<I>, Vec<I>, Vec<(I, I)>);
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fn parse_input(raw: &str) -> Parsed {
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let galaxies = raw
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.lines()
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.enumerate()
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.flat_map(|(x, l)| l.bytes().enumerate().filter_map(move |(y, b)| (b == b'#').then_some((x, y))))
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.collect_vec();
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let max = raw.lines().next().unwrap().len();
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let mut xs = vec![true; max];
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let mut ys = vec![true; max];
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for &(x, y) in galaxies.iter() {
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xs[x] = false;
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ys[y] = false;
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}
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(sliding_count(xs), sliding_count(ys), galaxies)
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}
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fn sliding_count(bools: Vec<bool>) -> Vec<I> {
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bools
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.into_iter()
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.scan(0, |prev, b| {
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*prev += b as I;
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Some(*prev)
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})
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.collect()
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}
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fn solve<const FACTOR: usize>((x_offset, y_offset, galaxies): &Parsed) -> usize {
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galaxies
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.iter()
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.map(|&(x, y)| (x + x_offset[x] * FACTOR, y + y_offset[y] * FACTOR))
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.tuple_combinations()
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.map(|((x1, y1), (x2, y2))| x1.abs_diff(x2) + y1.abs_diff(y2))
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.sum()
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}
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fn part1(parsed: &Parsed) -> usize {
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solve::<1>(parsed)
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}
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fn part2(parsed: &Parsed) -> usize {
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solve::<999_999>(parsed)
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}
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boilerplate! {
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TEST_INPUT == "\
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...#......
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.......#..
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#.........
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..........
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......#...
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.#........
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.........#
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..........
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.......#..
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#...#.....",
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tests: {
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part1: { TEST_INPUT => 374 },
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},
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bench1 == 9623138,
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bench2 == 726820169514,
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bench_parse: |(a, b, c): &Parsed| (a.len(), b.len(), c.len()) => (140, 140, 432),
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}
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