add day01 soulution

2024/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aoc2024"
+version = "0.1.0"

2024/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "aoc2024"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

2024/src/day01.rs

@@ -0,0 +1,47 @@
+use std::fs::read_to_string;
+
+fn read_as_vectors(input: &str) -> (Vec<i32>, Vec<i32>) {
+    let input = read_to_string(input).unwrap();
+    let (left, right): (Vec<_>, Vec<_>) = input
+        .lines()
+        .map(|x| {
+            let mut l = x.split_whitespace().map(|n| n.parse::<i32>().unwrap());
+            (l.next().unwrap(), l.next().unwrap())
+        })
+        .unzip();
+    (left, right)
+}
+
+pub fn stage1(input: &str) -> i32 {
+    let (mut left, mut right) = read_as_vectors(input);
+    left.sort();
+    right.sort();
+    let res: i32 = left
+        .iter()
+        .zip(right.iter())
+        .map(|(l, r)| (l - r).abs())
+        .sum();
+    res
+}
+
+pub fn stage2(input: &str) -> i32 {
+    let (left, right) = read_as_vectors(input);
+    left.iter()
+        .map(|l| right.iter().filter(|&f| *f == *l).count() as i32 * l)
+        .sum()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_stage1() {
+        assert_eq!(stage1("input/01_input.txt"), 1590491);
+    }
+
+    #[test]
+    fn test_stage2() {
+        assert_eq!(stage2("input/01_input.txt"), 22588371);
+    }
+}

2024/src/lib.rs

@@ -0,0 +1,2 @@
+#[allow(dead_code)]
+mod day01;