checkerboard-covering.py

# !/usr/bin/env python
# -*- coding: utf-8 -*-

"""
THE CHECKERBOARD COVERING

"""
__author__ = "prakashsellathurai"
__copyright__ = "Copyright 2021"
__version__ = "1.0.1"
__email__ = "prakashsellathurai@gmail.com"


def cover(board, lab=1, top=0, left=0, side=None):

    if side is None:
        side = len(board)

    s = side // 2

    offsets = (0, -1), (side - 1, 0)

    for dy_outer, dy_inner in offsets:
        for dx_outer, dx_inner in offsets:

            if not board[top + dy_outer][left + dx_outer]:
                board[top + s + dy_inner][left + s + dx_inner] = lab
    lab += 1
    if s > 1:
        for dy in [0, s]:
            for dx in [0, s]:
                lab = cover(board=board, lab=lab, top=top +
                            dy, left=left + dx, side=s)
    return lab


if __name__ == "__main__":
    board = [[0] * 8 for i in range(8)]
    board[7][7] = -1
    cover(board=board)
    for row in board:
        print((" %2i" * 8) % tuple(row))