Deel 1 van dag 5 aoc af, verder op pc

advent_of_code/2024/5/src/main.rs

@@ -0,0 +1,102 @@
+use std::collections::{HashMap, HashSet};
+
+use nom::{
+    bytes::complete::tag,
+    character::complete::{multispace1, u32},
+    multi::separated_list1,
+    sequence::separated_pair,
+    IResult,
+};
+
+fn parse(input: &str) -> IResult<&str, (Vec<(u32, u32)>, Vec<Vec<u32>>)> {
+    let (input, result) = separated_pair(
+        separated_list1(multispace1, separated_pair(u32, tag("|"), u32)),
+        multispace1,
+        separated_list1(multispace1, separated_list1(tag(","), u32)),
+    )(input)?;
+
+    Ok((input, result))
+}
+
+fn check_update(updates: &Vec<u32>, rules: &HashMap<u32, HashSet<u32>>) -> bool {
+    let mut forbidden: HashSet<u32> = HashSet::new();
+
+    updates.iter().all(|page| {
+        let lookup = forbidden.contains(page);
+
+        match rules.get(page) {
+            None => {}
+            Some(s) => {
+                for excl in s {
+                    forbidden.insert(*excl);
+                }
+            }
+        }
+
+        !lookup
+    })
+}
+
+fn solve_1(input: &str) -> u32 {
+    let (_, (rules, updates)) = parse(input).unwrap();
+
+    let mut exclusions: HashMap<u32, HashSet<u32>> = HashMap::new();
+    for (before, after) in rules.into_iter() {
+        match exclusions.get_mut(&after) {
+            None => {
+                exclusions.insert(after, HashSet::from([before]));
+            }
+            Some(s) => {
+                s.insert(before);
+            }
+        };
+    }
+
+    updates.into_iter().fold(0, |sum, update| {
+        sum + if check_update(&update, &exclusions) {
+            *update.get(update.len() / 2).unwrap()
+        } else {
+            0
+        }
+    })
+}
+
+fn solve_2(input: &str) -> u32 {
+    
+}
+
+fn main() {
+    println!("Hello, this is Patrick!");
+
+    let input = include_str!("../input.txt");
+
+    let result_1 = solve_1(input);
+    println!(
+        "The sum of correctly ordered middle page updates is {}",
+        result_1
+    );
+
+    let result_2 = solve_2(input);
+    println!(
+        "The sum of the incorrectly ordered middle page updates is {}",
+        result_2
+    );
+}
+
+#[cfg(test)]
+
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1() {
+        let test_input = include_str!("../test.txt");
+        assert_eq!(solve_1(test_input), 143);
+    }
+
+    #[test]
+    fn test_2() {
+        let test_input = include_str!("../test.txt");
+        assert_eq!(solve_2(test_input), 123);
+    }
+}