Maybe it is better to use var instead of let?

Thank you. I agree with you. I have just fixed it.

Thank you! I will fix it.

Thank you!

how can we avoid loop inside in the solution?

please, use let

nice job

please, use const or let when you define variables, it will cut an issue with global scope. Also I suggest to change name of variables. For example, behindRows and leftCols instead of factCols and factRow

It is the cool names of the variables, but why not const instead of let