advent-of-code/2019/04/src/main.rs
2019-12-04 22:18:55 +01:00

23 lines
751 B
Rust

#![feature(is_sorted)]
use itertools::Itertools;
pub fn main() {
let valid_part1 = (172_930..683_082)
.map(|n| n.to_string().chars().collect::<Vec<_>>())
.filter(|n| n.is_sorted())
.filter(|v| v.clone().iter().dedup().count() != v.len());
println!("Part 1: {}", valid_part1.clone().count());
let part2 = valid_part1.filter(|vec| {
vec.iter()
.group_by(move |n| *n)
.into_iter()
.filter_map(|(_, v)| if v.count() == 2 { Some(true) } else { None })
// can’t do this because I’m too smol brained for the borrow checker
//.filter(|(_, v)| v.count() == 2)
.count()
> 0
});
println!("Part 2: {}", part2.count());
}