adventofcode2022/day04/common.rs

// 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/>.

use std::io;
use std::ops::RangeInclusive;

pub struct Assignments {}

#[derive(Debug)]
pub struct Assignment {
    range1: RangeInclusive<u8>,
    range2: RangeInclusive<u8>,
}

impl Iterator for Assignments {
    type Item = Result<Assignment, &'static str>;

    fn next(&mut self) -> Option<Self::Item> {
        if let Some(line) = io::stdin().lines().next() {
            let line = line.unwrap();
            if line.len() > 0 {
                if let Some((left, right)) = line.split_once(',') {
                    if let (Some((s1, e1)), Some((s2, e2))) =
                        (left.split_once('-'), right.split_once('-'))
                    {
                        if let (Ok(s1), Ok(e1), Ok(s2), Ok(e2)) = (
                            s1.parse::<u8>(),
                            e1.parse::<u8>(),
                            s2.parse::<u8>(),
                            e2.parse::<u8>(),
                        ) {
                            return Some(Ok(Assignment::new(s1..=e1, s2..=e2)));
                        }
                    }
                }
                return Some(Err("input file contains invalid line"));
            }
        }
        None
    }
}

impl Assignment {
    pub fn new(range1: RangeInclusive<u8>, range2: RangeInclusive<u8>) -> Self {
        Self {
            range1: range1,
            range2: range2,
        }
    }

    pub fn has_obsolete_range(&self) -> bool {
        self.range1.contains(self.range2.start()) && self.range1.contains(self.range2.end())
            || self.range2.contains(self.range1.start()) && self.range2.contains(self.range1.end())
    }

    pub fn has_overlapping_ranges(&self) -> bool {
        self.range1.contains(self.range2.start())
            || self.range1.contains(self.range2.end())
            || self.range2.contains(self.range1.start())
            || self.range2.contains(self.range1.end())
    }
}