day1

1 files changed, 51 insertions, 0 deletions

diff --git a/src/bin/day1.rs b/src/bin/day1.rs
new file mode 100644
index 0000000..93d21d6
--- /dev/null
+++ b/src/bin/day1.rs
@@ -0,0 +1,51 @@
+static DAY: u8 = 1;
+
+fn main() {
+    let input = advent::read_lines(DAY);
+    println!("{DAY}a: {}", most_calories_elf(&input, 1));
+    println!("{DAY}b: {}", most_calories_elf(&input, 3));
+}
+
+fn most_calories_elf(input: &[String], elf_count: usize) -> u32 {
+    let mut input = input.to_vec();
+    let mut calories = Vec::new();
+    let mut current = 0;
+    input.push("".to_string());
+    for line in input {
+        if line.as_str().is_empty() {
+            calories.push(current);
+            current = 0;
+            continue;
+        }
+        current += line.parse::<u32>().unwrap();
+    }
+    calories.sort();
+    calories.iter().rev().take(elf_count).sum()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test() {
+        let input = [
+            "1000".to_string(),
+            "2000".to_string(),
+            "3000".to_string(),
+            "".to_string(),
+            "4000".to_string(),
+            "".to_string(),
+            "5000".to_string(),
+            "6000".to_string(),
+            "".to_string(),
+            "7000".to_string(),
+            "8000".to_string(),
+            "9000".to_string(),
+            "".to_string(),
+            "10000".to_string(),
+        ];
+        assert_eq!(most_calories_elf(&input, 1), 24000);
+        assert_eq!(most_calories_elf(&input, 3), 45000);
+    }
+}