Compilare: user.cpp: In function ‘int correct_par(std::__cxx11::string)’: user.cpp:28:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < par.size(); ++i) ~~^~~~~~~~~~~~ user.cpp: In function ‘std::pair<std::vector<int>, std::vector<int> > split_par(std::__cxx11::string)’: user.cpp:49:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < par.size(); ++i) ~~^~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:112:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.first.size(); ++i) cout << sol.first[i] << " "; ~~^~~~~~~~~~~~~~~~~~ user.cpp:115:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.second.size(); ++i) cout << sol.second[i] << " "; ~~^~~~~~~~~~~~~~~~~~~