Have a few doubts as below:

1, Can you explain further for this statement “The number at right is the possible step number you might need to used in total. ”? Not clear for assigned values.

2, What rule you mean in statement “ according to the rule, we should try the square which next to the right wall”?

3, What rule you mean in statement “ In fact, if according to the rule there is no need to close two (12,4,8) squares, I just mark it to make you understand it more clearly.”