Day 1, puzzle 1

src/d1p1.rs

@@ -0,0 +1,28 @@
+use std::io;
+
+fn main() {
+    println!("What's the calorie list?");
+    let lines = io::stdin().lines();
+    let mut was_empty = false;
+    let mut elves = vec![0];
+    for line in lines {
+        let line_s = line.unwrap();
+        if line_s.is_empty() {
+            if was_empty {
+                break;
+            }
+            elves.push(0);
+            was_empty = true;
+            continue;
+        } else {
+            was_empty = false;
+        }
+
+        let calories: u32 = line_s.parse().expect("Wanted a number");
+        let prev_calories = elves.pop().unwrap();
+        elves.push(prev_calories + calories);
+    }
+
+    let max = elves.iter().max().unwrap();
+    println!("The elf with the most calories is carrying {} cal", max);
+}