39 lines
929 B
Rust
39 lines
929 B
Rust
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use std::collections::{HashMap, HashSet};
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use aoc_runner_derive::{aoc as aoc_run, aoc_generator};
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type Contents = (HashSet<char>, HashSet<char>);
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fn get_priority(item: &char) -> u32 {
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if ('a'..='z').contains(item) {
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*item as u32 - 96
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} else {
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*item as u32 - 38
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}
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}
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#[aoc_generator(day3, part1)]
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fn parse_input(input: &str) -> Vec<Contents> {
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let mut out = Vec::with_capacity(input.len());
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for line in input.lines() {
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let half_len = line.len() / 2;
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let lo = HashSet::from_iter(line[0..half_len].chars());
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let hi = HashSet::from_iter(line[half_len..].chars());
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out.push((lo, hi));
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}
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out
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}
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#[aoc_run(day3, part1)]
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fn part1(sacks: &[Contents]) -> u32 {
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let mut out = 0;
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for sack in sacks {
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let (lo, hi) = sack;
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let common = lo.intersection(hi).into_iter().next().unwrap();
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out += get_priority(common);
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}
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out
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}
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