day1: Extract input parsing to lib

Cargo.toml

@@ -9,4 +9,3 @@ edition = "2021"
 
 [[bin]]
 name = "d1p1"
-path = "src/d1p1.rs"

src/bin/d1p1.rs

@@ -0,0 +1,8 @@
+use aoc22::day1;
+
+fn main() {
+    let elves = day1::read_elves();
+
+    let max = elves.iter().max().unwrap();
+    println!("The elf with the most calories is carrying {} cal", max);
+}

src/day1.rs

@@ -1,6 +1,6 @@
 use std::io;
 
-fn main() {
+pub fn read_elves() -> Vec<u32> {
     println!("What's the calorie list?");
     let lines = io::stdin().lines();
     let mut was_empty = false;
@@ -23,6 +23,5 @@ fn main() {
         elves.push(prev_calories + calories);
     }
 
-    let max = elves.iter().max().unwrap();
-    println!("The elf with the most calories is carrying {} cal", max);
+    elves
 }

src/lib.rs

@@ -0,0 +1 @@
+pub mod day1;