adventofcode/days/2023/02.rs

use advent_of_code::include_aoc;
use advent_of_code::strings::parsenumber;

include_aoc!(2023, 02);

#[derive(Debug, Clone, Copy)]
struct Take {
    red: u32,
    green: u32,
    blue: u32,
}

#[derive(Debug, Clone)]
struct Round {
    roundid: u32,
    takes: Vec<Take>,
}

#[derive(Debug, Clone, Copy)]
struct Sack {
    reds: u32,
    greens: u32,
    blues: u32,
}

impl Round {
    pub fn possible(&self, sack: Sack) -> bool {
        let mut ok = true;
        for take in self.takes.clone() {
            ok = ok
                && if sack.reds.checked_sub(take.red).is_none() {
                    false
                } else if sack.greens.checked_sub(take.green).is_none() {
                    false
                } else if sack.blues.checked_sub(take.blue).is_none() {
                    false
                } else {
                    true
                };
        }
        ok
    }
    fn power(&self) -> u64 {
        let mut sack = Sack {
            reds: 0,
            greens: 0,
            blues: 0,
        };
        for take in self.takes.clone() {
            if take.red > sack.reds {
                sack.reds = take.red
            }
            if take.green > sack.greens {
                sack.greens = take.green
            }
            if take.blue > sack.blues {
                sack.blues = take.blue
            }
        }
        sack.reds as u64 * sack.greens as u64 * sack.blues as u64
    }
}

impl From<&str> for Round {
    fn from(value: &str) -> Self {
        let doublecolon = value.find(':').unwrap();
        let mut round = Round {
            roundid: parsenumber(value.get(5..doublecolon).unwrap()),
            takes: Vec::<Take>::new(),
        };
        for taking in value.get(doublecolon + 1..).unwrap().split(";") {
            let mut take = Take {
                red: 0,
                green: 0,
                blue: 0,
            };
            for color in taking.split(',').map(str::trim) {
                let mut i = color.splitn(2, char::is_whitespace);
                let amount = parsenumber(i.next().unwrap());
                match i.next() {
                    Some("red") => take.red = amount,
                    Some("green") => take.green = amount,
                    Some("blue") => take.blue = amount,
                    None | Some(_) => panic!(),
                }
            }
            round.takes.push(take);
        }
        round
    }
}

fn main() {
    let mut gamerounds = Vec::<Round>::with_capacity(100);
    for game in DATA.split('\n') {
        gamerounds.push(game.into());
    }
    let sack = Sack {
        reds: 12,
        greens: 13,
        blues: 14,
    };
    let mut sum = 0;
    for round in gamerounds.clone() {
        if round.possible(sack) {
            sum += round.roundid;
        }
    }
    println!("Sum with putback: {}", sum);
    let mut sum = 0;
    for round in gamerounds {
        sum += round.power();
    }
    println!("Combined Power: {}", sum);
}