day 3, part 1 done

This commit is contained in:
Joe Ardent 2022-12-03 15:06:01 -08:00
parent 9b62fa0d92
commit 4ae6b3cb7f
2 changed files with 39 additions and 0 deletions

38
2022-aoc/src/d3.rs Normal file
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@ -0,0 +1,38 @@
use std::collections::{HashMap, HashSet};
use aoc_runner_derive::{aoc as aoc_run, aoc_generator};
type Contents = (HashSet<char>, HashSet<char>);
fn get_priority(item: &char) -> u32 {
if ('a'..='z').contains(item) {
*item as u32 - 96
} else {
*item as u32 - 38
}
}
#[aoc_generator(day3, part1)]
fn parse_input(input: &str) -> Vec<Contents> {
let mut out = Vec::with_capacity(input.len());
for line in input.lines() {
let half_len = line.len() / 2;
let lo = HashSet::from_iter(line[0..half_len].chars());
let hi = HashSet::from_iter(line[half_len..].chars());
out.push((lo, hi));
}
out
}
#[aoc_run(day3, part1)]
fn part1(sacks: &[Contents]) -> u32 {
let mut out = 0;
for sack in sacks {
let (lo, hi) = sack;
let common = lo.intersection(hi).into_iter().next().unwrap();
out += get_priority(common);
}
out
}

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@ -2,5 +2,6 @@ use aoc_runner_derive::aoc_lib;
mod d1;
mod d2;
mod d3;
aoc_lib! { year = 2022 }