Day 4 Part 1

src/days/day_4.rs

@@ -0,0 +1,105 @@
+use crate::days::solution::Solution;
+pub struct Day4P1 {}
+
+
+#[derive(Debug)]
+struct Card {
+    winning_numbers: Vec<u8>,
+    numbers: Vec<u8>,
+}
+
+impl Day4P1 {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl Solution for Day4P1 {
+    fn solve(&self, input: &str) -> u32 {
+        let parsed = parse_data(input);
+        calculate_day_4(parsed)
+    }
+
+    fn get_solution_name(&self) -> &str {
+        "Day 4 Part 1"
+    }
+}
+
+fn parse_data(input: &str) -> Vec<Card> {
+    let mut cards: Vec<Card> = Vec::new();
+
+    for line in input.lines() {
+        let mut card = Card {
+            winning_numbers: Vec::new(),
+            numbers: Vec::new(),
+        };
+
+        let mut line_split = line.split(":");
+        let id = line_split.next().unwrap().split(" ");
+
+        let mut numbers = line_split.next().unwrap().split("|");
+
+        let winning_numbers = numbers.next().unwrap().split(" ").collect::<Vec<&str>>();
+        let numbers = numbers.next().unwrap().split(" ").collect::<Vec<&str>>();
+
+        for number in winning_numbers {
+            if number.trim().is_empty() { continue; }
+            card.winning_numbers.push(number.trim().parse::<u8>().unwrap());
+        }
+
+        for number in numbers {
+            if number.trim().is_empty() { continue; }
+            card.numbers.push(number.trim().parse::<u8>().unwrap());
+        }
+
+        cards.push(card);
+    }
+
+    cards
+}
+
+fn calculate_day_4(cards: Vec<Card>) -> u32 {
+    let mut sum = 0;
+
+    for card in cards {
+        let mut matches: u32 = 0;
+
+        for number in card.winning_numbers {
+            if card.numbers.contains(&number) {
+                matches += 1;
+            }
+
+        }
+
+        if matches == 0 { continue; }
+        if matches == 1 {
+            sum += 1;
+            continue;
+        }
+
+        sum += 1 * 2u32.pow(matches-1);
+    }
+
+    sum
+}
+
+//tests
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_day_4_part_1() {
+        let day_4 = Day4P1 {};
+
+        let test_data = "Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11";
+
+        let parsed = parse_data(test_data);
+        assert_eq!(calculate_day_4(parsed), 13);
+    }
+}

src/days/mod.rs

@@ -2,4 +2,5 @@
 pub mod day_1;
 pub mod day_2;
 pub mod day_3;
+pub mod day_4;
 pub mod solution;