https://en.cppreference.com/w/cpp/numeric/math/sqrt

I have checked the following source: https://cplusplus.com/reference/cmath/sqrt/?kw=sqrt, and it did not say that std :: sqrt returns NaN when the argument is negative.
Could you please point out the source of your information? I will check that source if it is more reliable/updated.

Now that's some Code.

I am seeing your comment every where , whould You explain why it would fail?

you mean it evaluates to string each loop thus having O(n^2) time complexity

thanks for the recommendation but satan banned me from hell when he saw this code so no need to worry

bro, read clean code by Robert Cecil.
you are literally righting a spell to summon satan.

what is this 8x8 matrix ????
and why do you add 2 if start or finish is a corner

could you explaing your code to me in simple terms I really dont get what its doing or why you have -1 1 2 etc in your arrays

whats istringstream and getLine and what do they do exactly?
also whats the use of the variable Token?

I mean the best way to do it wound be O(nlog(n)) which would be a hastle to implement (or you use fancy libraries as other solutions do);