Compilare: user.cpp: In function ‘int main()’: user.cpp:33:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (lengthA > B.length()) ^ user.cpp:39:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < A.length();) ^ user.cpp:45:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = lengthA; i < B.length(); ++i) ^