main.rs

use std::collections::HashMap;
use std::fs::File;
use std::path::Path;
use std::io::Read;

// Given a Cell:
// if 0-2 neighbors are on, the cell goes OFF
// if 3-5 neighbors are on, the cell goes ON
// if 6-8 neighbors are on, the cell goes OFF

#[derive(Debug, PartialEq)]
enum Cell {
    ON,
    OFF,
}

type Board = Vec<Vec<Cell>>;

fn generate_board(config_path: &str) -> Board {
    let board_path = Path::new(config_path);
    let mut file: File = File::open(&board_path).ok().expect("Could not open file");
    let mut content: String = String::new();
    file.read_to_string(&mut content).ok().expect("Could not read file");
    let lines = content.trim().split("\n");
    let mut board = Board::new();

    for line in lines {
        let mut row = Vec::new();
        for character in line.chars() {
            let cell = match character {
                '1' => Cell::ON,
                '0' => Cell::OFF,
                _ => panic!("Invalid character"),
            };
            row.push(cell);
        }
        board.push(row);
    }
    board
}

// fn neighbors(coordinate: (usize, usize), board: &Board) -> Vec<Cell> {
//     let row_count = &board.len();
//     let column_count = &board[0].len();
// }

fn next_gen(coordinate: (usize, usize), board: &Board) -> Cell {
    // let (row, column) = coordinate;
    // let cell : &Cell = &board[row][column];
    Cell::OFF
}

fn step(board: &mut Board) {
    let mut cells_to_update: HashMap<(usize, usize), Cell> = HashMap::new();
    for (row_index, row) in board.iter().enumerate() {
        for (column_index, cell) in row.iter().enumerate() {
            let cell_next = next_gen((row_index, column_index), &board);
            if *cell != cell_next {
                cells_to_update.insert((row_index, column_index), cell_next);
            }
        }
    }

    println!("To Update: {:?}", cells_to_update);
    for ((row_index, column_index), cell) in cells_to_update {
        board[row_index][column_index] = cell;
    }
}

fn main() {
    let mut board: Board = generate_board("board.txt");
    step(&mut board);
    println!("{:?}", board);
}