Day 1, puzzle 1

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aoc23"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "aoc23"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[[bin]]
+name = "d1p1"
+path = "src/d1p1.rs"

src/d1p1.rs

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+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);
+}