Its not bad.
Just remember to make your code easy to understand to others.
Also try not to repeat yourself. You are calculating 3 times the where the half is.
Instead you can make a specific variable for it at the beginning solving both of your problems.

Someone can give me feedback about my solution?

I think your solution is way less efective, and in this top rated solution is problem with creating String s (it's redundant) we should just return new string from substring and that is it. Clear effictient and without redundancy :).

First comment I've left on this website; nice job

It's bad practice! Because every use of the substring method creates a new string. Hence we pollute the string pool. See mine....

String s is unnecessary. Just directly return word.substring(...).

very smart

dumb af

I just looked into it and your are right -0 is a thing however unless in string form it has no effect as 0 == -0. As well, this is only the case with floats and the desired return type is an integer. Because in java twos complete is used for integers -0 can't be created for integers.

No, no point.

Is there any point in this because 0 * (-1) == 0?