From 5c4e69b85996965d098972edb0b92dd7fb37483c Mon Sep 17 00:00:00 2001
From: cos <cos>
Date: Sun, 1 Dec 2019 14:32:16 +0100
Subject: Initial commit of solutions for adventofcode.com

With rust implementation for day01 of 2019.
---
 2019/rust/Cargo.toml        |  4 ++++
 2019/rust/day01/Cargo.toml  |  7 +++++++
 2019/rust/day01/src/main.rs | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 49 insertions(+)
 create mode 100644 2019/rust/Cargo.toml
 create mode 100644 2019/rust/day01/Cargo.toml
 create mode 100644 2019/rust/day01/src/main.rs

(limited to '2019/rust')

diff --git a/2019/rust/Cargo.toml b/2019/rust/Cargo.toml
new file mode 100644
index 0000000..f2bad2a
--- /dev/null
+++ b/2019/rust/Cargo.toml
@@ -0,0 +1,4 @@
+[workspace]
+members = [
+    "day01",
+]
diff --git a/2019/rust/day01/Cargo.toml b/2019/rust/day01/Cargo.toml
new file mode 100644
index 0000000..02d08dc
--- /dev/null
+++ b/2019/rust/day01/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "day01"
+version = "0.1.0"
+authors = ["cos <cos>"]
+edition = "2018"
+
+[dependencies]
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);
+}
-- 
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