Compilare: user.cpp: In function ‘int main()’: user.cpp:89:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ^ user.cpp:93:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<expresie.size();i++) ^ user.cpp:112:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ^