Day 2 in the books

Cargo.toml

@@ -15,3 +15,4 @@ test_lib = []
 
 [dependencies]
 pico-args = "0.5.0"
+regex = "1.10.2"

data/examples/02.txt

@@ -0,0 +1,5 @@
+Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green

src/bin/02.rs

@@ -0,0 +1,83 @@
+advent_of_code::solution!(2);
+
+use regex::Regex;
+
+pub fn part_one(input: &str) -> Option<u32> {
+    Some(
+        input
+            .lines()
+            .filter_map(|line| {
+                let game_re = Regex::new(r"^Game (\d+):").unwrap();
+                let red_re = Regex::new(r" (\d+) red").unwrap();
+                let green_re = Regex::new(r" (\d+) green").unwrap();
+                let blue_re = Regex::new(r" (\d+) blue").unwrap();
+                let game_id = game_re.captures(line).expect("Expected game_id to exist")[1]
+                    .parse::<u32>()
+                    .expect("Expect game_id to be an int");
+                let reds = red_re
+                    .captures_iter(line)
+                    .filter(|c| c[1].parse::<u32>().expect("Red capture should be int") > 12)
+                    .count();
+                let greens = green_re
+                    .captures_iter(line)
+                    .filter(|c| c[1].parse::<u32>().expect("Green capture should be int") > 13)
+                    .count();
+                let blues = blue_re
+                    .captures_iter(line)
+                    .filter(|c| c[1].parse::<u32>().expect("Blue capture should be int") > 14)
+                    .count();
+                if reds != 0 || greens != 0 || blues != 0 {
+                    None
+                } else {
+                    Some(game_id)
+                }
+            })
+            .sum(),
+    )
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    Some(
+        input
+            .lines()
+            .filter_map(|line| {
+                let red_re = Regex::new(r" (\d+) red").unwrap();
+                let green_re = Regex::new(r" (\d+) green").unwrap();
+                let blue_re = Regex::new(r" (\d+) blue").unwrap();
+                let reds = red_re
+                    .captures_iter(line)
+                    .map(|c| c[1].parse::<u32>().expect("Red capture should be int"))
+                    .reduce(|acc, e| if e > acc { e } else { acc })
+                    .unwrap();
+                let greens = green_re
+                    .captures_iter(line)
+                    .map(|c| c[1].parse::<u32>().expect("green capture should be int"))
+                    .reduce(|acc, e| if e > acc { e } else { acc })
+                    .unwrap();
+                let blues = blue_re
+                    .captures_iter(line)
+                    .map(|c| c[1].parse::<u32>().expect("blue capture should be int"))
+                    .reduce(|acc, e| if e > acc { e } else { acc })
+                    .unwrap();
+                Some(reds * greens * blues)
+            })
+            .sum(),
+    )
+}
+
+#[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, Some(8));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(2286));
+    }
+}