From bc4b69a40aa8a5e3d27a4826221bd059f119622d Mon Sep 17 00:00:00 2001
From: inga-lovinde <52715130+inga-lovinde@users.noreply.github.com>
Date: Sat, 12 Dec 2020 19:12:07 +0100
Subject: [PATCH] Solution for day 12

---
 day12-hard/Cargo.toml  |   9 +++
 day12-hard/src/main.rs | 130 +++++++++++++++++++++++++++++++++++++++++
 day12/Cargo.toml       |   9 +++
 day12/src/main.rs      | 126 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 274 insertions(+)
 create mode 100644 day12-hard/Cargo.toml
 create mode 100644 day12-hard/src/main.rs
 create mode 100644 day12/Cargo.toml
 create mode 100644 day12/src/main.rs

diff --git a/day12-hard/Cargo.toml b/day12-hard/Cargo.toml
new file mode 100644
index 0000000..e6ad9fa
--- /dev/null
+++ b/day12-hard/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "day12-hard"
+version = "0.1.0"
+authors = ["inga-lovinde <52715130+inga-lovinde@users.noreply.github.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/day12-hard/src/main.rs b/day12-hard/src/main.rs
new file mode 100644
index 0000000..67adda0
--- /dev/null
+++ b/day12-hard/src/main.rs
@@ -0,0 +1,130 @@
+use std::io::{self, BufRead};
+use std::error::Error;
+use std::str::FromStr;
+
+enum Command {
+    East(i64),
+    West(i64),
+    North(i64),
+    South(i64),
+    Left(i64),
+    Right(i64),
+    Forward(i64),
+}
+
+impl FromStr for Command {
+    type Err = Box<dyn Error>;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let first_char = match s.chars().next() {
+            Some(ch) => ch,
+            _ => {
+                return Err(Box::from("string is empty"));
+            }
+        };
+
+        let remainder: String = s.chars().skip(1).collect();
+        let value: i64 = remainder.parse()?;
+
+        Ok(match first_char {
+            'E' => Self::East(value),
+            'W' => Self::West(value),
+            'N' => Self::North(value),
+            'S' => Self::South(value),
+            'L' => Self::Left(value),
+            'R' => Self::Right(value),
+            'F' => Self::Forward(value),
+            _ => {
+                return Err(Box::from("unsupported first character"));
+            }
+        })
+    }
+}
+
+struct State {
+    ship_offset_north: i64,
+    ship_offset_east: i64,
+    waypoint_ship_offset_north: i64,
+    waypoint_ship_offset_east: i64,
+}
+
+impl State {
+    fn get_angle_cos(angle: i64) -> i64 {
+        match angle {
+            0 => 1,
+            90 => 0,
+            180 => -1,
+            270 => 0,
+            _ => panic!("Unsupported angle"),
+        }
+    }
+
+    fn get_angle_sin(angle: i64) -> i64 {
+        match angle {
+            0 => 0,
+            90 => 1,
+            180 => 0,
+            270 => -1,
+            _ => panic!("Unsupported angle"),
+        }
+    }
+
+    pub fn new() -> Self {
+        Self {
+            ship_offset_north: 0,
+            ship_offset_east: 0,
+            waypoint_ship_offset_north: 1,
+            waypoint_ship_offset_east: 10,
+        }
+    }
+
+    pub fn apply_command(&self, command: Command) -> Self {
+        match command {
+            Command::East(distance) => Self {
+                waypoint_ship_offset_east: self.waypoint_ship_offset_east + distance,
+                ..*self
+            },
+            Command::West(distance) => Self {
+                waypoint_ship_offset_east: self.waypoint_ship_offset_east - distance,
+                ..*self
+            },
+            Command::North(distance) => Self {
+                waypoint_ship_offset_north: self.waypoint_ship_offset_north + distance,
+                ..*self
+            },
+            Command::South(distance) => Self {
+                waypoint_ship_offset_north: self.waypoint_ship_offset_north - distance,
+                ..*self
+            },
+            Command::Left(angle) => Self {
+                waypoint_ship_offset_east: self.waypoint_ship_offset_east * Self::get_angle_cos(angle) - self.waypoint_ship_offset_north * Self::get_angle_sin(angle),
+                waypoint_ship_offset_north: self.waypoint_ship_offset_east * Self::get_angle_sin(angle) + self.waypoint_ship_offset_north * Self::get_angle_cos(angle),
+                ..*self
+            },
+            Command::Right(angle) => Self {
+                waypoint_ship_offset_east: self.waypoint_ship_offset_east * Self::get_angle_cos(angle) + self.waypoint_ship_offset_north * Self::get_angle_sin(angle),
+                waypoint_ship_offset_north: -self.waypoint_ship_offset_east * Self::get_angle_sin(angle) + self.waypoint_ship_offset_north * Self::get_angle_cos(angle),
+                ..*self
+            },
+            Command::Forward(times) => Self {
+                ship_offset_east: self.ship_offset_east + self.waypoint_ship_offset_east * times,
+                ship_offset_north: self.ship_offset_north + self.waypoint_ship_offset_north * times,
+                ..*self
+            },
+        }
+    }
+
+    pub fn get_manhattan_norm(&self) -> i64 {
+        self.ship_offset_east.abs() + self.ship_offset_north.abs()
+    }
+}
+
+fn main() {
+    let stdin = io::stdin();
+    let mut state = State::new();
+    for line in stdin.lock().lines() {
+        state = state.apply_command(line.unwrap().parse().unwrap());
+    }
+    
+    println!("{}", state.get_manhattan_norm());
+}
diff --git a/day12/Cargo.toml b/day12/Cargo.toml
new file mode 100644
index 0000000..12fb8d7
--- /dev/null
+++ b/day12/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "day12"
+version = "0.1.0"
+authors = ["inga-lovinde <52715130+inga-lovinde@users.noreply.github.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/day12/src/main.rs b/day12/src/main.rs
new file mode 100644
index 0000000..2b5ed74
--- /dev/null
+++ b/day12/src/main.rs
@@ -0,0 +1,126 @@
+use std::io::{self, BufRead};
+use std::error::Error;
+use std::str::FromStr;
+
+enum Command {
+    East(i64),
+    West(i64),
+    North(i64),
+    South(i64),
+    Left(i64),
+    Right(i64),
+    Forward(i64),
+}
+
+impl FromStr for Command {
+    type Err = Box<dyn Error>;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let first_char = match s.chars().next() {
+            Some(ch) => ch,
+            _ => {
+                return Err(Box::from("string is empty"));
+            }
+        };
+
+        let remainder: String = s.chars().skip(1).collect();
+        let value: i64 = remainder.parse()?;
+
+        Ok(match first_char {
+            'E' => Self::East(value),
+            'W' => Self::West(value),
+            'N' => Self::North(value),
+            'S' => Self::South(value),
+            'L' => Self::Left(value),
+            'R' => Self::Right(value),
+            'F' => Self::Forward(value),
+            _ => {
+                return Err(Box::from("unsupported first character"));
+            }
+        })
+    }
+}
+
+struct State {
+    offset_north: i64,
+    offset_east: i64,
+    angle: i64,
+}
+
+impl State {
+    fn get_angle_cos(&self) -> i64 {
+        match self.angle {
+            0 => 1,
+            90 => 0,
+            180 => -1,
+            270 => 0,
+            _ => panic!("Unsupported angle"),
+        }
+    }
+
+    fn get_angle_sin(&self) -> i64 {
+        match self.angle {
+            0 => 0,
+            90 => 1,
+            180 => 0,
+            270 => -1,
+            _ => panic!("Unsupported angle"),
+        }
+    }
+
+    pub fn new() -> Self {
+        Self {
+            offset_north: 0,
+            offset_east: 0,
+            angle: 0
+        }
+    }
+
+    pub fn apply_command(&self, command: Command) -> Self {
+        match command {
+            Command::East(distance) => Self {
+                offset_east: self.offset_east + distance,
+                ..*self
+            },
+            Command::West(distance) => Self {
+                offset_east: self.offset_east - distance,
+                ..*self
+            },
+            Command::North(distance) => Self {
+                offset_north: self.offset_north + distance,
+                ..*self
+            },
+            Command::South(distance) => Self {
+                offset_north: self.offset_north - distance,
+                ..*self
+            },
+            Command::Left(angle) => Self {
+                angle: (self.angle + angle).rem_euclid(360),
+                ..*self
+            },
+            Command::Right(angle) => Self {
+                angle: (self.angle - angle).rem_euclid(360),
+                ..*self
+            },
+            Command::Forward(distance) => Self {
+                offset_east: self.offset_east + self.get_angle_cos() * distance,
+                offset_north: self.offset_north + self.get_angle_sin() * distance,
+                ..*self
+            },
+        }
+    }
+
+    pub fn get_manhattan_norm(&self) -> i64 {
+        self.offset_east.abs() + self.offset_north.abs()
+    }
+}
+
+fn main() {
+    let stdin = io::stdin();
+    let mut state = State::new();
+    for line in stdin.lock().lines() {
+        state = state.apply_command(line.unwrap().parse().unwrap());
+    }
+    
+    println!("{}", state.get_manhattan_norm());
+}