75 lines
1.9 KiB
Rust
75 lines
1.9 KiB
Rust
use crate::puzzle::Puzzle;
|
|
use nom::{
|
|
Parser,
|
|
character::complete::{char, digit1, newline},
|
|
combinator::{eof, map_res},
|
|
error::Error,
|
|
multi::separated_list1,
|
|
sequence::{separated_pair, terminated},
|
|
};
|
|
|
|
pub const PUZZLE: Puzzle<Vec<(usize, usize)>, usize, 2> = Puzzle {
|
|
number: 2,
|
|
parser: |input| {
|
|
terminated(
|
|
terminated(
|
|
separated_list1(
|
|
char(','),
|
|
separated_pair(parse_int(), char('-'), parse_int()),
|
|
),
|
|
newline,
|
|
),
|
|
eof,
|
|
)
|
|
.parse(input)
|
|
.unwrap()
|
|
.1
|
|
},
|
|
parts: [
|
|
|input| {
|
|
input
|
|
.into_iter()
|
|
.flat_map(|(l, u)| {
|
|
(*l..(u + 1)).flat_map(|n| if is_repetition_2(n) { Some(n) } else { None })
|
|
})
|
|
.sum()
|
|
},
|
|
|input| {
|
|
input
|
|
.into_iter()
|
|
.flat_map(|(l, u)| {
|
|
(*l..(u + 1)).flat_map(|n| if is_repetition_n(n) { Some(n) } else { None })
|
|
})
|
|
.sum()
|
|
},
|
|
],
|
|
};
|
|
|
|
fn is_repetition_2(n: usize) -> bool {
|
|
let n = n.to_string();
|
|
let l = n.len();
|
|
let d = l / 2;
|
|
let r = l % 2;
|
|
if r == 0 { equal_chunks(&n, d) } else { false }
|
|
}
|
|
|
|
fn is_repetition_n(n: usize) -> bool {
|
|
let n = n.to_string();
|
|
let l = n.len();
|
|
let d = l / 2;
|
|
(1..(d + 1)).any(|i| equal_chunks(&n, i))
|
|
}
|
|
|
|
fn equal_chunks(n: &String, i: usize) -> bool {
|
|
let chars = n.chars().collect::<Vec<char>>();
|
|
let mut chunks = (chars[..]).chunks(i);
|
|
match chunks.next() {
|
|
None => true,
|
|
Some(x) => chunks.all(|y| y == x),
|
|
}
|
|
}
|
|
|
|
fn parse_int<'a>() -> impl Parser<&'a str, Output = usize, Error = Error<&'a str>> {
|
|
map_res(digit1, |s: &str| s.parse::<usize>())
|
|
}
|