don't mutate the input grid. ;p

Hello, I implemented some solution but it does not pass some 5x5 and some random test. I displayed input to debug test and see what's wrong and I don't understand the case with word ANIMALITY.
The board looks like this:

T T M D A
G Y \u0000 \u0000 \u0000
P A L C E
I A U L G
A M I N A

I can't see any solution here. And is that correct that test passes default char value as input?
Thank you.

@Voile is correct: be sure to consider all possibilities, as your while condition might be weaker than you think.

Also, try to post using git flavoured markdown for better readability, thanks :)

What if n=0?