AOC 23 Day 2

main.rs

#![allow(dead_code, unused_variables, unused_mut)]

use std::env;
use std::fs::File;
use std::io::{self, BufRead};

struct Game {
    id: u32,
    r: u32,
    g: u32,
    b: u32
}

use std::fmt;

impl fmt::Display for Game {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}: r {} g {} b {}", self.id, self.r, self.g, self.b)
    }
}

fn main() {
    let args: Vec<String> = env::args().collect();
    if args.len() != 2 {
        eprintln!("Usage: {} <filename>", args[0]);
        std::process::exit(1);
    }
    let filename = &args[1];

    let file = match File::open(filename) {
        Ok(file) => file,
        Err(error) => {
            eprintln!("Error opening file {}: {}", filename, error);
            std::process::exit(1);
        }
    };

    let reader = io::BufReader::new(file);

    let mut games: Vec<Game> = Vec::new();
    for (line_number, line) in reader.lines().enumerate() {
        match line {
            Ok(line_content) => {
                games.push(parse_game(line_number, line_content));
            }
            Err(error) => {
                eprintln!("Error reading line {}: {}", line_number + 1, error);
            }
        }
    }

    println!("Total = {}", part2(games));
}

fn parse_game(line_number: usize, line_content: String) -> Game {
    let mut game = Game {
        id: 0,
        r: 0,
        g: 0,
        b: 0,
    };

    let v: Vec<&str> = line_content.split(&[';', ' ', ',', ':']).filter(|s| !s.is_empty()).collect();
    //println!("Vec is {:?}", v);

    // parse out game id
    game.id = v[1].parse::<u32>().expect(format!("Line {} does not produce a number", line_number).as_str());

    for inx in (2..v.len()).step_by(2) {
        let num = v[inx].parse::<u32>().expect(format!("Line {} does not produce a number", line_number).as_str());
        match v[inx+1] {
            "blue" => {
                if num > game.b { game.b = num }
            },
            "green" => {
                if num > game.g { game.g = num }
            },
            "red" => {
                if num > game.r { game.r = num }
            },
            _ => panic!("What the fuck lads")
        }
    }
    game
}

fn part1(games: Vec<Game>) -> u32 {
    let filter_game = Game {
        id: 0,
        r: 12,
        g: 13,
        b: 14,
    };
    games.iter().fold(0,
      |sum, g|
          {
              //println!("Checking filter game {} vs game {}", filter_game, g);
              if filter_game.r >= g.r && filter_game.g >= g.g && filter_game.b >= g.b {
                  sum + g.id
              } else {
                  sum
              }
          }
    )
}

fn part2(games: Vec<Game>) -> u32 {
    games.iter().fold(0,|sum, g| sum + (g.r * g.g * g.b))
}