I am trying to solve this question. I am facing difficulty in understanding the diagram of test case 2. As far as I have understood the question, the question asks to check whether is it possible to create 180 degree rotated image by changing colour of any possible combination of blocks exactly k times. If we look at the second sample test case 2, it's image is So, it's 180 degree rotated image should look like this But, in the question the rotated image is give like this

I am unable to understand how is it possible? Please explain the logic behind it.

My next question is that