Compilare: main.cpp: In function 'bool verif_sir(std::__cxx11::string)': main.cpp:27:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); ++i) ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:92:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < s.size(); ++j) ~~^~~~~~~~~~