From: Greg Burri <greg.burri@gmail.com>
Date: Sat, 4 Dec 2021 21:04:09 +0000 (+0100)
Subject: Day 2 part 1
X-Git-Url: https://git.euphorik.ch/?a=commitdiff_plain;h=f863361915b298e93fe3be460b79f94108197661;p=advent_of_code_2021.git

Day 2 part 1
---

diff --git a/src/day02.rs b/src/day02.rs
new file mode 100644
index 0000000..44f8ce3
--- /dev/null
+++ b/src/day02.rs
@@ -0,0 +1,78 @@
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum Movement {
+    Forward(u32),
+    Down(u32),
+    Up(u32),
+}
+
+pub struct Position {
+    pub horizontal: i32,
+    pub depth: i32,
+}
+
+pub fn parse_movements(movements: &str) -> Vec<Movement> {
+    movements
+        .split('\n')
+        .map(|line| {
+            let trimmed_lowercase_line = line.trim().to_lowercase();
+            let command_and_distance: Vec<&str> = trimmed_lowercase_line.split(' ').collect();
+            let distance = command_and_distance[1].parse::<u32>().unwrap();
+            match command_and_distance[0] {
+                "forward" => Movement::Forward(distance),
+                "down" => Movement::Down(distance),
+                "up" => Movement::Up(distance),
+                _ => Movement::Forward(0)
+            }
+        })
+        .collect()
+}
+
+pub fn get_final_position(movements: &[Movement]) -> Position {
+    let mut pos = Position { horizontal: 0, depth: 0 };
+    for m in movements {
+        match m {
+            Movement::Forward(d) => pos.horizontal += *d as i32,
+            Movement::Down(d) => pos.depth += *d as i32,
+            Movement::Up(d) => pos.depth -= *d as i32,
+        }
+    }
+    pos
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parsing() {
+        let commands_str =
+            "forward 5
+             down 5
+             forward 8
+             up 3
+             down 8
+             forward 2";
+
+        let commands = parse_movements(commands_str);
+        assert_eq!(commands, Vec::from([Movement::Forward(5), Movement::Down(5), Movement::Forward(8), Movement::Up(3), Movement::Down(8), Movement::Forward(2)]));
+    }
+
+    #[test]
+    fn part1() {
+        let commands =
+            parse_movements(
+                "forward 5
+                 down 5
+                 forward 8
+                 up 3
+                 down 8
+                 forward 2"
+            );
+        let final_position = get_final_position(&commands);
+        assert_eq!(final_position.horizontal * final_position.depth, 150);
+    }
+
+    #[test]
+    fn part2() {
+    }
+}
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index d3592a1..eb070cb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,14 +1,22 @@
 use std::env;
+use std::fs;
 use std::time::Instant;
 
 mod common;
 mod day01;
+mod day02;
 
 fn day01() -> String {
     let report = common::read_list_of_numbers("data/day01.input", "\n");
     format!("part1: {}, part2: {}", day01::count_number_of_decreased_values(&report, 1), day01::count_number_of_decreased_values(&report, 3))
 }
 
+fn day02() -> String {
+    let movements = day02::parse_movements(&fs::read_to_string("data/day02.input").unwrap());
+    let final_position = day02::get_final_position(&movements);
+    format!("part1: {}, part2: {}", final_position.horizontal * final_position.depth, "")
+}
+
 fn format_micros(t: u128) -> String {
     if t < 10_000 {
         format!("{} μs", t)
@@ -29,6 +37,7 @@ fn main() {
 
     let days: Vec<fn() -> String> = vec!(
         day01,
+        day02,
     );
 
     let args: Vec<String> = env::args().skip(1).collect();