tictactoe.py

use std::io::{self, BufRead};
use std::process::exit;

const PLAYER_SYMBOL: [&str; 2] = ["X", "O"];
// TODO use enum instead of string representation
// TODO maybe use Display for printing proper values

fn main() {
    let mut board: [[&str; 3]; 3] = [[" ", " ", " "], [" ", " ", " "], [" ", " ", " "]];
    let mut current_player: usize = 0;
    let mut moves_count: u8 = 0;

    loop {
        get_player_input(&mut board, current_player);
        moves_count += 1;
        print_board(board);
        if current_player_won(board, PLAYER_SYMBOL[current_player]) {
            println!("Player {} won!", PLAYER_SYMBOL[current_player]);
            break;
        }
        if moves_count == 9 {
            println!("Nobody won");
            break;
        }
        current_player = (current_player == 0) as usize;
    }
}

fn current_player_won(board: [[&str; 3]; 3], current_player: &str) -> bool {
    // horizontal
    for i in 0..3 {
        if board[i][0] == current_player
            && board[i][1] == current_player
            && board[i][2] == current_player
        {
            return true;
        }
    }
    // vertical
    for i in 0..3 {
        if board[0][i] == current_player
            && board[1][i] == current_player
            && board[2][i] == current_player
        {
            return true;
        }
    }
    // diagonal
    if board[0][0] == current_player
        && board[1][1] == current_player
        && board[2][2] == current_player
    {
        return true;
    }
    if board[0][2] == current_player
        && board[1][1] == current_player
        && board[2][0] == current_player
    {
        return true;
    }
    return false;
}

fn get_player_input(board: &mut [[&str; 3]; 3], current_player: usize) {
    loop {
        // TODO Use Option or Result with ? operator instead of default values
        let mut x: usize = 100;
        let mut y: usize = 100;
        println!("Enter coordinates (ex. 2,3): ");
        // TODO https://doc.rust-lang.org/std/io/struct.Stdin.html#method.read_line
        let mut line = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line = line.trim().to_owned();

        // splitting just once - https://doc.rust-lang.org/std/primitive.str.html#method.split_once
        let coordinates: Vec<&str> = line.split(",").collect();
        if coordinates.len() == 2 {
            x = coordinates[0].parse::<usize>().unwrap_or(100);
            y = coordinates[1].parse::<usize>().unwrap_or(100);
        }
        if x < 4 && x > 0 && y < 4 && y > 0 {
            if board[x - 1][y - 1] == " " {
                board[x - 1][y - 1] = PLAYER_SYMBOL[current_player];
                return;
            }
        }
        println!("Wrong input, try again");
    }
}

fn print_board(board: [[&str; 3]; 3]) {
    for i in 0..3 {
        println!("{}", board[i].join("|"));
        if i < 2 {
            println!("-----");
        }
    }
}