Day 04

2022/src/bin/04.rs

@@ -0,0 +1,88 @@
+use advent_of_code::helpers::parse_input;
+use std::collections::HashSet;
+
+type Range = HashSet<u32>;
+
+fn create_range(min: u32, max: u32) -> Range {
+    let mut set: HashSet<u32> = HashSet::new();
+    for i in min..max + 1 {
+        set.insert(i);
+    }
+
+    set
+}
+
+fn from_str(txt: &str) -> Option<Range> {
+    let mut nums = txt.split('-').map(|n| n.parse::<u32>());
+    match (nums.next(), nums.next()) {
+        (Some(Ok(min)), Some(Ok(max))) => Some(create_range(min, max)),
+
+        _ => None,
+    }
+}
+
+fn is_subsets(set_pair: &Vec<Range>) -> bool {
+    let (first_set, second_set) = (&set_pair[0], &set_pair[1]);
+
+    first_set.is_subset(second_set) || second_set.is_subset(first_set)
+}
+
+fn get_ranges_pairs(input: &str) -> Vec<Vec<Range>> {
+    let rngs: Vec<Vec<Range>> = parse_input(input, |pair| {
+        pair.split(',')
+            .map(from_str)
+            .map(|rng| rng.unwrap())
+            .collect()
+    });
+
+    rngs
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let rngs = get_ranges_pairs(input);
+    let subsets: Vec<bool> = rngs.iter().map(is_subsets).collect();
+
+    let count: usize = subsets.iter().filter(|&b| *b).count();
+
+    Some(count as u32)
+}
+
+fn contains_at_all(set_pair: &Vec<Range>) -> bool {
+    let (first_set, second_set) = (&set_pair[0], &set_pair[1]);
+
+    let intersection: HashSet<u32> = first_set.intersection(second_set).copied().collect();
+
+    !intersection.is_empty()
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    let rngs = get_ranges_pairs(input);
+    let subsets: Vec<bool> = rngs.iter().map(contains_at_all).collect();
+
+    let count: usize = subsets.iter().filter(|&b| *b).count();
+
+    Some(count as u32)
+}
+
+fn main() {
+    let input = &advent_of_code::read_file("inputs", 4);
+    advent_of_code::solve!(1, part_one, input);
+    advent_of_code::solve!(2, part_two, input);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let input = advent_of_code::read_file("examples", 4);
+        assert_eq!(part_one(&input), Some(2));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let input = advent_of_code::read_file("examples", 4);
+        assert_eq!(part_two(&input), Some(4));
+    }
+}

2022/src/examples/04.txt

@@ -0,0 +1,6 @@
+2-4,6-8
+2-3,4-5
+5-7,7-9
+2-8,3-7
+6-6,4-6
+2-6,4-8

2022/src/helpers.rs

@@ -3,8 +3,6 @@
  * Example import from this file: `use advent_of_code::helpers::example_fn;`.
  */
 
-use std::collections::HashSet;
-
 pub fn parse_input<T>(input: &str, cons: fn(&str) -> T) -> Vec<T>
 where
     Vec<T>: FromIterator<T>,