Advent of Code solutions
Day 5
+127
-5
+71
-5
years/2024/src/day_5.rs
+71
-5
years/2024/src/day_5.rs
···
1
+
2
+
use std::collections::{HashMap, HashSet};
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3
2
4
use advent_core::{Day, day_stuff, ex_for_day};
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5
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pub struct Day5;
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7
8
+
#[derive(Clone, Debug)]
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pub struct Rules(HashMap<i64,Vec<i64>>);
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impl Rules {
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pub fn take(&mut self, lhs: i64, rhs: i64) {
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self.0.entry(lhs).and_modify(|seen| { seen.push(rhs); }).or_insert(vec![rhs]);
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}
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fn good(&self, up: &[i64]) -> bool {
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let mut seen = HashSet::new();
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for u in up.iter() {
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if self.0.get(u).is_none_or(|should| should.iter().all(|s| !seen.contains(s))) {
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seen.insert(*u);
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} else {
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return false;
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}
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}
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true
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}
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+
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fn sort_to_rules(&self, up: &mut[i64]) {
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while !self.good(up) {
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self.sort_step(up);
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}
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}
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fn sort_step(&self, up: &mut[i64]) {
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for i in 0..up.len()-1 {
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for j in i+1..up.len() {
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if self.0.get(&up[j]).is_some_and(|shld| shld.contains(&up[i])) {
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up.swap(i, j);
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}
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}
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}
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}
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}
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impl Day for Day5 {
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day_stuff!(5, "", "");
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day_stuff!(5, "143", "123", (Rules, Vec<Vec<i64>>));
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fn part_1(_input: Self::Input) -> Option<String> {
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-
None
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fn part_1(input: Self::Input) -> Option<String> {
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let (rules, updates) = input;
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let ans = updates.into_iter().filter_map(|up| {
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if rules.good(&up) {
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Some(up[up.len() / 2])
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} else {
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None
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}
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}).sum::<i64>();
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Some(ans.to_string())
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}
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-
fn part_2(_input: Self::Input) -> Option<String> {
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-
None
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fn part_2(input: Self::Input) -> Option<String> {
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let (rules, updates) = input;
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let ans = updates.into_iter().filter_map(|mut up| {
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if !rules.good(&up) {
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rules.sort_to_rules(&mut up);
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Some(up[up.len() / 2])
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} else {
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None
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}
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}).sum::<i64>();
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Some(ans.to_string())
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}
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fn parse_input(input: &str) -> Self::Input {
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let (rules, updates) = input.split_once("\n\n").unwrap();
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let mut rules_o = Rules(HashMap::with_capacity(50));
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for l in rules.lines() {
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let (lhs, rhs) = l.split_once('|').unwrap();
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rules_o.take(lhs.parse().unwrap(), rhs.parse().unwrap());
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}
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(rules_o, updates.split('\n').map(|l| l.split(',').map(|x| x.parse().unwrap()).collect()).collect())
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}
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}
+28
years/2024/src/examples/day_5/1.txt
+28
years/2024/src/examples/day_5/1.txt
···
1
+
47|53
2
+
97|13
3
+
97|61
4
+
97|47
5
+
75|29
6
+
61|13
7
+
75|53
8
+
29|13
9
+
97|29
10
+
53|29
11
+
61|53
12
+
97|53
13
+
61|29
14
+
47|13
15
+
75|47
16
+
97|75
17
+
47|61
18
+
75|61
19
+
47|29
20
+
75|13
21
+
53|13
22
+
23
+
75,47,61,53,29
24
+
97,61,53,29,13
25
+
75,29,13
26
+
75,97,47,61,53
27
+
61,13,29
28
+
97,13,75,29,47
+28
years/2024/src/examples/day_5/2.txt
+28
years/2024/src/examples/day_5/2.txt
···
1
+
47|53
2
+
97|13
3
+
97|61
4
+
97|47
5
+
75|29
6
+
61|13
7
+
75|53
8
+
29|13
9
+
97|29
10
+
53|29
11
+
61|53
12
+
97|53
13
+
61|29
14
+
47|13
15
+
75|47
16
+
97|75
17
+
47|61
18
+
75|61
19
+
47|29
20
+
75|13
21
+
53|13
22
+
23
+
75,47,61,53,29
24
+
97,61,53,29,13
25
+
75,29,13
26
+
75,97,47,61,53
27
+
61,13,29
28
+
97,13,75,29,47