Added day 2 code for part 1 and 2

Signed-off-by: Louis Vallat <louis@louis-vallat.xyz>

day2/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "day2"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

day2/src/main.rs

@@ -0,0 +1,57 @@
+use std::{fs, env, vec};
+
+
+fn read_input(path: &str) -> String {
+    return fs::read_to_string(path).expect("Cannot read file.");
+}
+
+fn parse_input(s: &str) -> Vec<(String, i32)> {
+    let mut r:Vec<(String, i32)> = vec![];
+    let v = s.split("\n").into_iter();
+    for e in v {
+        let p = e.split_whitespace().collect::<Vec<&str>>();
+        if p.len() == 2 && p[1].parse::<i32>().is_ok() {
+            r.push((p[0].to_owned(), p[1].parse::<i32>().unwrap()));
+        }
+    }
+    return r;
+}
+
+fn compute_horizontal_depth_aim(t: (String, i32), a: (i32, i32, i32)) -> (i32, i32, i32) {
+    return match t.0.as_str() {
+        "up" => (a.0, a.1, a.2 - t.1),
+        "down" => (a.0, a.1, a.2 + t.1),
+        "forward" => (a.0 + t.1, a.1 + a.2 * t.1, a.2),
+        _ => a
+    };
+}
+
+fn compute_horizontal_depth(t: (String, i32), a: (i32, i32)) -> (i32, i32) {
+    return match t.0.as_str() {
+        "up" => (a.0, a.1 - t.1),
+        "down" => (a.0, a.1 + t.1),
+        "forward" => (a.0 + t.1, a.1),
+        _ => a
+    };
+}
+
+fn get_horizontal_depth_aim(v: Vec<(String, i32)>) -> (i32, i32, i32) {
+    return v.into_iter().fold((0, 0, 0), |acc, e| compute_horizontal_depth_aim(e, acc));
+}
+
+fn get_horizontal_depth(v: Vec<(String, i32)>) -> (i32, i32) {
+    return v.into_iter().fold((0, 0), |acc, e| compute_horizontal_depth(e, acc));
+}
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    for arg in args.iter().skip(1) {
+        let v = parse_input(&read_input(&arg));
+        let r1 = get_horizontal_depth(v.clone());
+        let r2 = get_horizontal_depth_aim(v);
+        println!("[{}]", &arg);
+        println!("\tPart 1 {} x {} = {}", r1.0, r1.1, r1.0 * r1.1);
+        println!("\tPart 2 {} x {} = {}", r2.0, r2.1, r2.0 * r2.1);
+    }
+}
+