Compilare: user.cpp: In function ‘int main()’: user.cpp:17:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s1.size(); i++) ^ user.cpp:22:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s2.size(); i++) ^ user.cpp:55:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i++) ^