Setup

src/day1/mod.rs

@@ -0,0 +1,63 @@
+use std::collections::HashSet;
+
+pub struct Day1 {
+    pub input: String,
+}
+
+impl Day1 {
+    pub fn new() -> Day1 {
+        let input = include_bytes!("input");
+        let input = String::from_utf8_lossy(input);
+        Day1 {
+            input: input.to_string(),
+        }
+    }
+
+    pub fn part_one(&self) {
+        let mut left: Vec<i32> = Vec::new();
+        let mut right: Vec<i32> = Vec::new();
+        self.input.lines().for_each(|line| {
+            let mut parts = line.split_whitespace();
+            left.push(parts.next().unwrap().parse().unwrap());
+            right.push(parts.next().unwrap().parse().unwrap());
+        });
+
+        left.sort();
+        right.sort();
+
+        let res = left
+            .iter()
+            .zip(right.iter())
+            .map(|(l, r)| Day1::abs(*l, *r))
+            .sum::<i32>();
+
+        println!("{}", res);
+    }
+
+    fn abs(a: i32, b: i32) -> i32 {
+        if a > b {
+            a - b
+        } else {
+            b - a
+        }
+    }
+
+    pub fn part_two(&self) {
+        let mut left: HashSet<i32> = HashSet::new();
+        let mut right: Vec<i32> = Vec::new();
+        self.input.lines().for_each(|line| {
+            let mut parts = line.split_whitespace();
+            left.insert(parts.next().unwrap().parse().unwrap());
+            right.push(parts.next().unwrap().parse().unwrap());
+        });
+
+        let mut acc = 0;
+        for r in right.iter() {
+            if left.contains(r) {
+                acc = acc + *r;
+            }
+        }
+
+        println!("{}", acc);
+    }
+}