day 2 part 2

day2/src/main.rs

@@ -1,9 +1,10 @@
 fn main() {
     let input = std::fs::read_to_string("input.txt").unwrap();
 
-    let result = valid_game_id_sum(&input);
+    let game_id_sum = valid_game_id_sum(&input);
+    let pow = game_pow_sum(&input);
 
-    println!("Result: {}", result);
+    println!("Game ID sum: {}, Total game pow: {}", game_id_sum, pow);
 }
 
 const MAX_RED: u32 = 12;
@@ -11,46 +12,70 @@ const MAX_GREEN: u32 = 13;
 const MAX_BLUE: u32 = 14;
 
 fn valid_game_id_sum(game_list: &str) -> u32 {
-    let res: u32 = game_list.lines().filter_map(|game| {
-        let (left, right) = game.split_once(": ").unwrap();
-        if game_validity_check(right.trim()) {
-            let game_id: u32 = left.trim_start_matches("Game ").parse().unwrap();
-            Some(game_id)
-        }
-        else {
-            None
-        }
-    }).sum();
+    let res: u32 = game_list
+        .lines()
+        .filter_map(|game| {
+            let (left, right) = game.split_once(": ").unwrap();
+            if let (true, _) = game_check(right.trim()) {
+                let game_id: u32 = left.trim_start_matches("Game ").parse().unwrap();
+                Some(game_id)
+            } else {
+                None
+            }
+        })
+        .sum();
 
     res
 }
 
-fn game_validity_check(game: &str) -> bool {
+fn game_pow_sum(game_list: &str) -> u32 {
+    game_list
+        .lines()
+        .map(|game| {
+            let (_, right) = game.split_once(": ").unwrap();
+            let (_, pow) = game_check(right.trim());
+            pow
+        })
+        .sum()
+}
+
+fn game_check(game: &str) -> (bool, u32) {
+    let mut min_red = 0;
+    let mut min_green = 0;
+    let mut min_blue = 0;
+    let mut valid = true;
     for set in game.split("; ") {
         let colors = set.split(", ");
         for color in colors {
             let (count, col) = color.split_once(' ').unwrap();
             let count: u32 = count.parse().unwrap();
-            let invalid = match col {
-                "red" => count > MAX_RED,
-                "green" => count > MAX_GREEN,
-                "blue" => count > MAX_BLUE,
+            match col {
+                "red" => {
+                    min_red = min_red.max(count);
+                    valid = valid && count <= MAX_RED;
+                }
+                "green" => {
+                    min_green = min_green.max(count);
+                    valid = valid && count <= MAX_GREEN;
+                }
+                "blue" => {
+                    min_blue = min_blue.max(count);
+                    valid = valid && count <= MAX_BLUE;
+                }
                 _ => panic!("invalid color"),
             };
-            if invalid {
-                return false;
-            }
         }
     }
 
-    true
+    let pow = min_red * min_green * min_blue;
+    (valid, pow)
 }
 
 #[cfg(test)]
 mod test {
-    use crate::valid_game_id_sum;
+    use crate::*;
 
-    const PART_1_EXAMPLE: &str = "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+    const EXAMPLE: &str = "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
@@ -58,6 +83,11 @@ Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green";
 
     #[test]
     fn part_1_example() {
-        assert_eq!(8, valid_game_id_sum(PART_1_EXAMPLE));
+        assert_eq!(8, valid_game_id_sum(EXAMPLE));
     }
-}
+
+    #[test]
+    fn part_2_example() {
+        assert_eq!(2286, game_pow_sum(EXAMPLE));
+    }
+}