Chess Board Cell Color

chess.rs

// Task
// Given two cells on the standard chess board, determine whether they have the same color or not.
// 
// Example
// For cell1 = "A1" and cell2 = "C3", the output should be true.

const BOARD_SIZE: usize = 9;

fn chessboard_cell_color(cell1: &str, cell2: &str) -> bool {
    let mut board = [false; BOARD_SIZE * BOARD_SIZE];
    for (i, e) in board.iter_mut().enumerate() {
        if  i % 2 == 0 {
            *e = !*e
        }
    }
    let pos = |x: usize, y: usize| y * BOARD_SIZE + x;
    let conver_letter_to_num = |l| match l {
        "A" => 1,
        "B" => 2,
        "C" => 3,
        "D" => 4,
        "E" => 5,
        "F" => 6,
        "G" => 7,
        "H" => 8,
        _ => panic!("Out of boundaries"),
    };
    let (x1, y1) = {
        let (x1, y1) = cell1.split_at(1);
        (conver_letter_to_num(x1), y1.parse().unwrap())
    };
    let (x2, y2) = {
        let (x2, y2) = cell2.split_at(1);
        (conver_letter_to_num(x2), y2.parse().unwrap())
    };
    let pos_a = pos(x1, y1);
    let pos_b = pos(x2, y2);
    board[pos_a] == board[pos_b]
}

#[test]
fn basic_tests() {
    assert_eq!(chessboard_cell_color("A1", "C3"), true);
    assert_eq!(chessboard_cell_color("A1", "H1"), false);
    assert_eq!(chessboard_cell_color("A2", "H2"), false);
    assert_eq!(chessboard_cell_color("A3", "H3"), false);
    assert_eq!(chessboard_cell_color("A4", "H4"), false);
    assert_eq!(chessboard_cell_color("A5", "H5"), false);
    assert_eq!(chessboard_cell_color("A6", "H6"), false);
    assert_eq!(chessboard_cell_color("A7", "H7"), false);
    assert_eq!(chessboard_cell_color("A4", "H4"), false);
    assert_eq!(chessboard_cell_color("A1", "H3"), false);
    assert_eq!(chessboard_cell_color("A1", "A2"), false);
    assert_eq!(chessboard_cell_color("A1", "C1"), true);
    assert_eq!(chessboard_cell_color("A1", "A1"), true);
}

fn get_sum(cell: &str) -> u8 {
    cell.chars().map(|c| c as u8).sum()
}

fn chessboard_cell_color(cell1: &str, cell2: &str) -> bool {
    get_sum(cell1) % 2 ==  get_sum(cell2) % 2
}