The message about hardcoded solution is just a general information.
If your code fails one of the validators it means that it is not handling one of the edge cases correctly.
You can experiment with Custom test cases to try and figure it out (you must enable Expert mode in settings to see it).
Try something like this (not the actual validator, but similar):
5
aA##c
#a##c
b###C
bBb#c
##bcc
Expected output is
C 5