feat: upload day-5

Author: Nitestack

2024/day-5/Cargo.lock

@@ -0,0 +1,6 @@
+[package]
+name = "day-5"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

2024/day-5/Cargo.toml

@@ -0,0 +1,50 @@
+// ╭─────────────────────────────────────────────────────────╮
+// │ Advent of Code 2024 - Day 5                             │
+// ╰─────────────────────────────────────────────────────────╯
+
+use std::cmp::Ordering;
+
+fn main() {
+    let (unparsed_rules, unparsed_updates) = include_str!("../input.txt").split_once("\n\n").expect("Invalid input");
+    let rules = unparsed_rules.lines()
+        .map(|line| line.split_once("|").unwrap())
+        .map(|(a, b)| (a.parse::<u32>().unwrap(), b.parse::<u32>().unwrap()))
+        .collect::<Vec<_>>();
+    let updates = unparsed_updates.lines()
+        .map(|line| line.split(",").map(|page| page.parse::<u32>().unwrap()).collect::<Vec<_>>())
+        .collect::<Vec<_>>();
+    // ── Part 1 ──────────────────────────────────────────────────────────
+    let result_part1 = updates.iter()
+        .filter(|update| rules.iter().all(|rule| complies_with_rule(rule, update)))
+        .map(|update| update[update.len() / 2])
+        .sum::<u32>();
+
+    println!("Result: {}", result_part1);
+    // ── Part 2 ──────────────────────────────────────────────────────────
+    let result_part2 = updates.iter()
+        .filter(|update| !rules.iter().all(|rule| complies_with_rule(rule, update)))
+        .map(|update| {
+            let mut sorted_update = update.clone();
+            sorted_update.sort_unstable_by(|a, b| {
+                match rules.iter().find(|&(x, y)| (x == a || x == b) && (y == a || y == b)) {
+                    Some((x, y)) => {
+                        if a == x && b == y { Ordering::Less }
+                        else { Ordering::Greater }
+                    },
+                    None => Ordering::Equal
+                }
+            });
+            sorted_update
+        })
+        .map(|update| update[update.len() / 2])
+        .sum::<u32>();
+    println!("Result: {}", result_part2);
+}
+
+fn complies_with_rule(rule: &(u32, u32), update: &Vec<u32>) -> bool {
+    let (a, b) = rule;
+
+    !update.contains(&a)
+        || !update.contains(&b)
+        || update.iter().position(|page| page == a).unwrap() < update.iter().position(|page| page == b).unwrap()
+}