1 files changed, 38 insertions, 0 deletions
diff --git a/2019/rust/day01/src/main.rs b/2019/rust/day01/src/main.rs
new file mode 100644
index 0000000..c984e80
--- /dev/null
+++ b/2019/rust/day01/src/main.rs
@@ -0,0 +1,38 @@
+use std::io::{self, BufRead};
+
+fn read_input() -> Vec<i32> {
+    let stdin = io::stdin();
+    let nums: Vec<i32> = stdin.lock().lines().map(|x| x.unwrap().parse().unwrap()).collect();
+    nums
+}
+
+fn first_puzzle(payloads:&Vec<i32>) -> i32 {
+    let fuel = payloads.iter().fold(0, |fuel, mass| fuel + mass/3-2);
+
+    fuel
+}
+
+fn second_puzzle(payloads:&Vec<i32>) -> i32 {
+    fn fuel_required(mass:&i32) -> i32 {
+        let fuel = mass/3-2;
+
+        if fuel > 0 {
+            fuel + fuel_required(&fuel)
+        } else {
+            0
+        }
+    }
+
+    let fuel = payloads.iter().fold(0, |fuel, mass| fuel + fuel_required(mass));
+    fuel
+}
+
+fn main() {
+    let payloads = read_input();
+
+    let first = first_puzzle(&payloads);
+    println!("first: {}", first);
+
+    let second = second_puzzle(&payloads);
+    println!("second: {}", second);
+}