Compilare: main.cpp: In function 'std::__cxx11::string f(int, int)': main.cpp:32:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(aPos < a.size()) ~~~~~^~~~~~~~~~ main.cpp:38:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = bPos; i < b.size(); i++) ~~^~~~~~~~~~ main.cpp:46:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ans == q.size()) ~~~~^~~~~~~~~~~ main.cpp:56:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = bPos; i < b.size(); i++) ~~^~~~~~~~~~