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|
struct Position {
x: i32,
y: i32,
}
struct AimedPosition {
pos: Position,
aim: i32,
}
fn main() {
let input = advent::read_lines(2);
let pos = drive_course(Position {x: 0, y: 0}, &input);
println!("2a: {}", pos.x * pos.y);
let pos = drive_course_aimed(Position {x: 0, y: 0}, &input);
println!("2b: {}", pos.x * pos.y);
}
fn move_submarine(pos: Position, cmd: &str) -> Position {
let tokens : Vec<&str> = cmd.split(' ').collect();
let direction = tokens[0];
let distance = tokens[1].parse::<i32>().unwrap();
let mut pos = pos;
match direction {
"forward" => {
pos.x += distance;
},
"down" => {
pos.y += distance;
},
"up" => {
pos.y -= distance;
},
_ => panic!("invalid direction: {}", direction)
};
pos
}
fn move_submarine_aimed(pos: AimedPosition, cmd: &str) -> AimedPosition {
let tokens : Vec<&str> = cmd.split(' ').collect();
let direction = tokens[0];
let distance = tokens[1].parse::<i32>().unwrap();
let mut pos = pos;
match direction {
"forward" => {
pos.pos.x += distance;
pos.pos.y += pos.aim * distance;
},
"down" => {
pos.aim += distance;
},
"up" => {
pos.aim -= distance;
},
_ => panic!("invalid direction: {}", direction)
};
pos
}
fn drive_course<T: AsRef<str>>(start: Position, course: &[T]) -> Position {
let mut pos = start;
for cmd in course {
pos = move_submarine(pos, cmd.as_ref());
}
pos
}
fn drive_course_aimed<T: AsRef<str>>(start: Position, course: &[T]) -> Position {
let mut pos = AimedPosition { pos: start, aim: 0 };
for cmd in course {
pos = move_submarine_aimed(pos, cmd.as_ref());
}
pos.pos
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test() {
let course = [
"forward 5",
"down 5",
"forward 8",
"up 3",
"down 8",
"forward 2",
];
let pos = drive_course(Position {x: 0, y: 0}, &course);
assert_eq!(pos.x * pos.y, 150);
let pos = drive_course_aimed(Position {x: 0, y: 0}, &course);
assert_eq!(pos.x * pos.y, 900);
}
}
|
