Advent of Code solutions
2024 Day 1
+36
-8
+1
-1
advent_core/src/parser.rs
+1
-1
advent_core/src/parser.rs
+23
-5
years/2024/src/day_1.rs
+23
-5
years/2024/src/day_1.rs
···
1
+
2
+
use std::collections::HashMap;
1
3
2
4
use advent_core::{Day, day_stuff, ex_for_day};
3
5
···
5
7
6
8
impl Day for Day1 {
7
9
8
-
day_stuff!(1, "", "");
10
+
day_stuff!(1, "11", "31", (Vec<i32>, Vec<i32>));
9
11
10
-
fn part_1(_input: Self::Input) -> Option<String> {
11
-
None
12
+
fn part_1(input: Self::Input) -> Option<String> {
13
+
let (mut l, mut r) = input;
14
+
l.sort_unstable();
15
+
r.sort_unstable();
16
+
Some(l.into_iter().zip(r.into_iter()).map(|(l, r)| (l - r).abs()).sum::<i32>().to_string())
12
17
}
13
18
14
-
fn part_2(_input: Self::Input) -> Option<String> {
15
-
None
19
+
fn part_2(input: Self::Input) -> Option<String> {
20
+
let (l, r) = input;
21
+
let apr = r.into_iter().fold(HashMap::new(), |mut a, curr| {
22
+
a.entry(curr).and_modify(|x| { *x += 1 }).or_insert(1);
23
+
a
24
+
});
25
+
Some(l.into_iter().map(|l| l * apr.get(&l).unwrap_or(&0)).sum::<i32>().to_string())
16
26
}
27
+
28
+
fn parse_input(input: &str) -> Self::Input {
29
+
input.split("\n").map(|l| {
30
+
let mut l = l.trim().split_ascii_whitespace();
31
+
(l.next().map(|x| x.parse::<i32>().unwrap()).unwrap(), l.next().map(|x| x.parse::<i32>().unwrap()).unwrap())
32
+
}).collect::<(Vec<_>, Vec<_>)>()
33
+
}
34
+
17
35
}