main.rs

fn display(board: [char; 9]) {
    for row in 0..3 {
        println!(
            " {} | {} | {}",
            board[row * 3],
            board[row * 3 + 1],
            board[row * 3 + 2]
        );
        if row == 0 || row == 1 {
            println!("---+---+---");
        }
        
    }
}

fn main() {
    let board = ['.'; 9];

    display(board);
}