Q:

Does using inline keyword in methods definition may cause ptoblems?

I used inline in every method in my program (implementation of algorithm), does it can make problems?

A:

Depends on what your code looks like.
But not understanding what your code means? That is definitely going to cause you problems.
Why don't you try to learn what inline actually does, rather than simply whether or not it's going to cause any problems?
The primary effect of the inline keyword in C++ is to make the compiler suppress the ODR (One Definition Rule). So a non-inline function must be defined in exactly one translation unit.
An inline function must be defined in every translation where it's used.
So depending on how and where your function is defined, inline may or may not be correct. I suggest you use it where its use is correct.

