Compilare: user.cpp: In function ‘void oglinda(std::__cxx11::string&)’: user.cpp:12:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); i++) ~~^~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); i += k) { ~~^~~~~~~~~~ user.cpp:37:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i + k <= s.size()) { ~~~~~~^~~~~~~~~~~ user.cpp:63:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v[i].size() <= bit || v[i][bit] == '0') { ~~~~~~~~~~~~^~~~~~