Add day1

.gitignore

@@ -0,0 +1 @@
+*input.txt

day1/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day1"
+version = "0.1.0"

day1/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "day1"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

day1/src/main.rs

@@ -0,0 +1,39 @@
+fn parse(input: &str) -> (Vec<u32>, Vec<u32>) {
+    input
+        .lines()
+        .map(|line| {
+            let tmp = line.split_once(' ');
+            (
+                tmp.unwrap().0.parse::<u32>().unwrap(),
+                tmp.unwrap().1.trim().parse::<u32>().unwrap(),
+            )
+        })
+        .collect()
+}
+
+fn part1(input: &(Vec<u32>, Vec<u32>)) -> u32 {
+    let mut firsts = input.0.clone();
+    let mut seconds = input.1.clone();
+    firsts.sort_unstable();
+    seconds.sort_unstable();
+    firsts
+        .iter()
+        .zip(seconds.iter())
+        .map(|(f, s)| u32::abs_diff(*f, *s))
+        .sum()
+}
+
+fn part2(input: &(Vec<u32>, Vec<u32>)) -> u32 {
+    input
+        .0
+        .iter()
+        .map(|num| num * input.1.iter().filter(|x| x == &num).count() as u32)
+        .sum()
+}
+
+fn main() {
+    let input = include_str!("../input.txt");
+    let parsed_input = parse(input);
+    println!("{}", part1(&parsed_input));
+    println!("{}", part2(&parsed_input));
+}