You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
116 lines
2.3 KiB
116 lines
2.3 KiB
use std::char;
|
|
|
|
pub fn solve(input: &str) -> String {
|
|
let arrangement = vec![
|
|
vec![None, None, Some('1'), None, None],
|
|
vec![None, Some('2'), Some('3'), Some('4'), None],
|
|
vec![Some('5'), Some('6'), Some('7'), Some('8'), Some('9')],
|
|
vec![None, Some('A'), Some('B'), Some('C'), None],
|
|
vec![None, None, Some('D'), None, None],
|
|
];
|
|
let mut keypad = Keypad {
|
|
arrangement: arrangement,
|
|
current: (0, 2),
|
|
};
|
|
|
|
let mut answer = String::new();
|
|
for c in input.chars() {
|
|
match c {
|
|
'U' => {
|
|
keypad.move_(Dir::Up);
|
|
}
|
|
'D' => {
|
|
keypad.move_(Dir::Down);
|
|
}
|
|
'L' => {
|
|
keypad.move_(Dir::Left);
|
|
}
|
|
'R' => {
|
|
keypad.move_(Dir::Right);
|
|
}
|
|
'\n' => {
|
|
answer.push(keypad.button());
|
|
}
|
|
_ => {
|
|
unreachable!();
|
|
}
|
|
}
|
|
}
|
|
answer.push(keypad.button());
|
|
answer
|
|
}
|
|
|
|
#[test]
|
|
fn test_solve() {
|
|
let instructions = "ULL
|
|
RRDDD
|
|
LURDL
|
|
UUUUD";
|
|
|
|
assert_eq!(solve(instructions), "5DB3".to_string());
|
|
}
|
|
|
|
struct Keypad {
|
|
arrangement: Vec<Vec<Option<char>>>,
|
|
current: (usize, usize),
|
|
}
|
|
|
|
impl Keypad {
|
|
fn move_(&mut self, dir: Dir) {
|
|
let (dx, dy): (isize, isize) = match dir {
|
|
Dir::Up => (0, -1),
|
|
Dir::Down => (0, 1),
|
|
Dir::Left => (-1, 0),
|
|
Dir::Right => (1, 0),
|
|
};
|
|
|
|
let x = (self.current.0 as isize + dx) as usize;
|
|
let y = (self.current.1 as isize + dy) as usize;
|
|
|
|
if self.button_at(x, y).is_some() {
|
|
self.current = (x, y);
|
|
}
|
|
}
|
|
|
|
fn button(&self) -> char {
|
|
let (x, y) = self.current;
|
|
self.arrangement[y][x].unwrap()
|
|
}
|
|
|
|
fn button_at(&self, x: usize, y: usize) -> Option<char> {
|
|
self.arrangement.get(y).and_then(|row| row.get(x).and_then(|c| *c))
|
|
}
|
|
}
|
|
|
|
enum Dir {
|
|
Up,
|
|
Down,
|
|
Left,
|
|
Right,
|
|
}
|
|
|
|
#[test]
|
|
fn test_keypad() {
|
|
let arrangement = vec![
|
|
vec!['1', '2', '3'],
|
|
vec!['4', '5', '6'],
|
|
vec!['7', '8', '9'],
|
|
]
|
|
.iter()
|
|
.map(|row| row.iter().map(|x| Some(*x)).collect())
|
|
.collect();
|
|
let mut keypad = Keypad {
|
|
arrangement: arrangement,
|
|
current: (1, 1),
|
|
};
|
|
|
|
assert_eq!(keypad.button_at(1, 1), Some('5'));
|
|
assert_eq!(keypad.button(), '5');
|
|
|
|
keypad.move_(Dir::Up);
|
|
assert_eq!(keypad.button(), '2');
|
|
|
|
keypad.move_(Dir::Up);
|
|
assert_eq!(keypad.button(), '2');
|
|
}
|