creates a submarine trait

day2/src/main.rs

@@ -1,6 +1,6 @@
 mod models;
 
-use models::{Command, Submarine};
+use models::{Command, Submarine, SubmarineV1, SubmarineV2};
 use std::fs::File;
 use std::io::{self, BufRead, BufReader, Lines, Result};
 use std::iter::Iterator;
@@ -9,15 +9,23 @@ use std::path::Path;
 static INPUT_PATH: &str = "input.txt";
 
 fn main() -> Result<()> {
-    let submarine = Submarine { xcord: 0, depth: 0 };
+    // First puzzle
+    let submarine_v1 = SubmarineV1::new();
     let commands = read_commands(INPUT_PATH)?;
-    let submarine = apply_commands(submarine, &commands);
-    println!("First puzzle: {}", submarine.depth * submarine.xcord);
+    let submarine_v1 = apply_commands(submarine_v1, &commands);
+    println!("First puzzle: {}", submarine_v1.position_x_depth());
+    // Second puzzle
+    let submarine_v2 = SubmarineV2::new();
+    let submarine_v2 = apply_commands(submarine_v2, &commands);
+    println!("Second puzzle: {}", submarine_v2.position_x_depth());
     Ok(())
 }
 
-fn apply_commands(submarine: Submarine, commands: &[Command]) -> Submarine {
-    commands.iter().copied().fold(submarine, Submarine::exec)
+fn apply_commands(submarine: impl Submarine, commands: &[Command]) -> impl Submarine {
+    commands
+        .iter()
+        .copied()
+        .fold(submarine, |submarine, command| submarine.exec(command))
 }
 
 fn read_commands(file_path: &str) -> Result<Vec<Command>> {

day2/src/models/command.rs

@@ -0,0 +1,20 @@
+#[derive(Debug, Clone, Copy)]
+pub enum Command {
+    Forward(i32),
+    Down(i32),
+    Up(i32),
+}
+
+impl From<String> for Command {
+    fn from(str: String) -> Self {
+        let words: Vec<&str> = str.split_ascii_whitespace().collect();
+        let action = words[0];
+        let unit: i32 = words[1].parse().unwrap();
+        match action {
+            "forward" => Command::Forward(unit),
+            "down" => Command::Down(unit),
+            "up" => Command::Up(unit),
+            _ => panic!("Invalid command {}", action),
+        }
+    }
+}

day2/src/models/mod.rs

@@ -1,57 +1,5 @@
-#[derive(Debug, Clone, Copy)]
-pub struct Submarine {
-    pub xcord: i32,
-    pub depth: i32,
-}
+mod command;
+mod submarines;
 
-impl Submarine {
-    pub fn exec(submarine: Self, command: Command) -> Self {
-        match command {
-            Command::Forward(unit) => Self::forward(submarine, unit),
-            Command::Down(unit) => Self::down(submarine, unit),
-            Command::Up(unit) => Self::up(submarine, unit),
-        }
-    }
-
-    fn forward(submarine: Self, unit: i32) -> Self {
-        Submarine {
-            xcord: submarine.xcord + unit,
-            depth: submarine.depth,
-        }
-    }
-
-    fn down(submarine: Self, unit: i32) -> Self {
-        Submarine {
-            xcord: submarine.xcord,
-            depth: submarine.depth + unit,
-        }
-    }
-
-    fn up(submarine: Self, unit: i32) -> Self {
-        Submarine {
-            xcord: submarine.xcord,
-            depth: submarine.depth - unit,
-        }
-    }
-}
-
-#[derive(Debug, Clone, Copy)]
-pub enum Command {
-    Forward(i32),
-    Down(i32),
-    Up(i32),
-}
-
-impl From<String> for Command {
-    fn from(str: String) -> Self {
-        let words: Vec<&str> = str.split_ascii_whitespace().collect();
-        let action = words[0];
-        let unit: i32 = words[1].parse().unwrap();
-        match action {
-            "forward" => Command::Forward(unit),
-            "down" => Command::Down(unit),
-            "up" => Command::Up(unit),
-            _ => panic!("Invalid command {}", action),
-        }
-    }
-}
+pub use command::Command;
+pub use submarines::{Submarine, SubmarineV1, SubmarineV2};

day2/src/models/submarines.rs

@@ -0,0 +1,120 @@
+use super::Command;
+
+pub trait Submarine {
+    fn exec(&self, command: Command) -> Self;
+    fn position(&self) -> i32;
+    fn depth(&self) -> i32;
+    fn position_x_depth(&self) -> i32 {
+        self.position() * self.depth()
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct SubmarineV1 {
+    pub xcord: i32,
+    pub depth: i32,
+}
+
+impl SubmarineV1 {
+    pub fn new() -> Self {
+        Self { xcord: 0, depth: 0 }
+    }
+
+    fn forward(self, unit: i32) -> Self {
+        SubmarineV1 {
+            xcord: self.xcord + unit,
+            depth: self.depth,
+        }
+    }
+
+    fn down(self, unit: i32) -> Self {
+        SubmarineV1 {
+            xcord: self.xcord,
+            depth: self.depth + unit,
+        }
+    }
+
+    fn up(self, unit: i32) -> Self {
+        SubmarineV1 {
+            xcord: self.xcord,
+            depth: self.depth - unit,
+        }
+    }
+}
+
+impl Submarine for SubmarineV1 {
+    fn exec(&self, command: Command) -> Self {
+        match command {
+            Command::Forward(unit) => self.forward(unit),
+            Command::Down(unit) => self.down(unit),
+            Command::Up(unit) => self.up(unit),
+        }
+    }
+
+    fn position(&self) -> i32 {
+        self.xcord
+    }
+
+    fn depth(&self) -> i32 {
+        self.depth
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct SubmarineV2 {
+    pub xcord: i32,
+    pub depth: i32,
+    pub aim: i32,
+}
+
+impl SubmarineV2 {
+    pub fn new() -> Self {
+        Self {
+            xcord: 0,
+            depth: 0,
+            aim: 0,
+        }
+    }
+
+    fn forward(self, unit: i32) -> Self {
+        SubmarineV2 {
+            xcord: self.xcord + unit,
+            depth: self.depth + self.aim * unit,
+            aim: self.aim,
+        }
+    }
+
+    fn down(self, unit: i32) -> Self {
+        SubmarineV2 {
+            xcord: self.xcord,
+            depth: self.depth,
+            aim: self.aim + unit,
+        }
+    }
+
+    fn up(self, unit: i32) -> Self {
+        SubmarineV2 {
+            xcord: self.xcord,
+            depth: self.depth,
+            aim: self.aim - unit,
+        }
+    }
+}
+
+impl Submarine for SubmarineV2 {
+    fn exec(&self, command: Command) -> Self {
+        match command {
+            Command::Forward(unit) => self.forward(unit),
+            Command::Down(unit) => self.down(unit),
+            Command::Up(unit) => self.up(unit),
+        }
+    }
+
+    fn position(&self) -> i32 {
+        self.xcord
+    }
+
+    fn depth(&self) -> i32 {
+        self.depth
+    }
+}