Loopless version

src/bin/day1.rs

@@ -7,23 +7,15 @@ fn main() -> Result<(), Box<dyn Error>> {
     let file = File::open("inputs/day1.txt")?;
     let lines = io::BufReader::new(file).lines().map(|l| l.unwrap());
 
-    let mut elves = Vec::<Vec<u32>>::new();
-
-    let mut current_elf = Vec::<u32>::new();
-    for line in lines {
-        if line != "" {
-            let calories = line.parse().unwrap();
-            current_elf.push(calories);
-        } else {
-            elves.push(current_elf);
-            current_elf = Vec::<u32>::new();
-        }
-    }
-
-    let mut calories_per_elf: Vec<u32> = elves
-        .iter()
-        .map(|e| e.iter().fold(0, |a, b| a + b))
-        .collect();
+    let mut calories_per_elf: Vec<u32> =
+        lines.map(|l| l.parse::<u32>()).fold(vec![0], |mut v, c| {
+            if let Ok(cal) = c {
+                *v.last_mut().unwrap() += cal;
+            } else {
+                v.push(0);
+            };
+            v
+        });
 
     calories_per_elf.sort();
     calories_per_elf.reverse();