Added day 5 part 1

src/bin/05.rs

@@ -0,0 +1,89 @@
+use std::collections::HashMap;
+
+advent_of_code::solution!(5);
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let manual = Manual::from(input);
+    let mut sum = 0;
+
+    manual
+        .updates
+        .iter()
+        .filter(|&update| manual.is_correct_order(&update))
+        .for_each(|update| {
+            let mid = update.len() / 2;
+            sum += update[mid]
+        });
+
+    Some(sum)
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    None
+}
+
+struct Manual {
+    rules: Vec<(u32, u32)>,
+    updates: Vec<Vec<u32>>,
+}
+
+impl Manual {
+    fn is_correct_order(&self, update: &Vec<u32>) -> bool {
+        let map: HashMap<u32, usize> = update
+            .iter()
+            .enumerate()
+            .map(|(idx, &page)| (page, idx))
+            .collect();
+
+        self.rules
+            .iter()
+            .all(|(x, y)| match (map.get(x), map.get(y)) {
+                (Some(&x), Some(&y)) => x < y,
+                _ => true,
+            })
+    }
+}
+
+impl From<&str> for Manual {
+    fn from(input: &str) -> Self {
+        let manual: Vec<&str> = input.split("\n\n").collect();
+        let (rules, updates) = (manual[0], manual[1]);
+
+        let rules: Vec<(u32, u32)> = rules
+            .lines()
+            .map(|rule| {
+                let parts: Vec<u32> = rule.split('|').filter_map(|num| num.parse().ok()).collect();
+                (parts[0], parts[1])
+            })
+            .collect();
+
+        let updates: Vec<Vec<u32>> = updates
+            .lines()
+            .map(|update| {
+                update
+                    .split(',')
+                    .filter_map(|num| num.parse::<u32>().ok())
+                    .collect()
+            })
+            .collect();
+
+        Self { rules, updates }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+}