Compilare: user.cpp: In function ‘int main()’: user.cpp:75:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0, j = 0; i < v.size(); ){ ^ user.cpp:76:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( ; j < v.size() && v[j].first >= v[i].first - d; ++j){ ^ user.cpp:84:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( ; k < v.size() && v[i].first <= v[k].first; ++k){ ^ user.cpp: In member function ‘int mk_vecini::operator()(int, int)’: user.cpp:28:20: warning: control reaches end of non-void function [-Wreturn-type] return x + m; } } }; ^