Initial skeleton code for 2020

2020/src/day01.rs

@@ -0,0 +1,40 @@
+use std::io::Read;
+
+use crate::common::from_lines;
+use crate::Solution;
+
+#[derive(Default)]
+pub struct Day01;
+
+fn fuel_required(weight: u32) -> u32 {
+    (weight / 3).saturating_sub(2)
+}
+
+fn recursive_fuel(mut weight: u32) -> u32 {
+    let mut required = 0;
+
+    while weight > 0 {
+        weight = fuel_required(weight);
+        required += weight
+    }
+
+    required
+}
+
+impl Solution for Day01 {
+    fn part1(&mut self, input: &mut dyn Read) -> String {
+        let weights: Vec<u32> = from_lines(input);
+
+        let fuel_required: u32 = weights.into_iter().map(fuel_required).sum();
+
+        fuel_required.to_string()
+    }
+
+    fn part2(&mut self, input: &mut dyn Read) -> String {
+        let weights: Vec<u32> = from_lines(input);
+
+        let fuel_required: u32 = weights.into_iter().map(recursive_fuel).sum();
+
+        fuel_required.to_string()
+    }
+}