Checkerboard Detection

Problem

Check whether a binary mask is a perfect checkerboard.

A mask is a checkerboard when mask[i][j] always equals (mask[0][0] + i + j) mod 2. An empty mask counts as a checkerboard.

Hint

Compare each cell with (top-left value + row + column) mod 2.

case 1

in: [[[1,0,1],[0,1,0],[1,0,1]]]

expected: true

case 2

in: [[[0,1],[1,0]]]

expected: true

case 3

in: [[[1,1],[0,1]]]

expected: false

case 4

in: [[[1]]]

expected: true

case 5

in: [[]]

expected: true

Starter codePython

def is_checkerboard(mask):
    # Your code here
    pass

5 test cases · run your code against them in the editor