adventofcode2022/day09/part2.rs

29 lines
1004 B
Rust

// Copyright 2022 Christian Ulrich
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// usage: ./part2 < input
pub mod common;
use std::collections::HashSet;
fn main() -> Result<(), &'static str> {
let tail_positions: Result<HashSet<(isize, isize)>, _> = common::rope_states::<10>()
.map(|s| Ok(s?.tail_pos()))
.collect();
println!("{}", tail_positions?.len());
Ok(())
}