Compilare: user.cpp: In function ‘int main()’: user.cpp:54:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( long i = 0; i < v.size ( ); i++ ) { ^ user.cpp:60:34: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘std::vector<std::pair<double, double> >::size_type {aka unsigned int}’ [-Wformat=] printf ( "%ld\n", q.size ( ) ); ^ user.cpp:61:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( long i = 0; i < q.size ( ); i++ ) ^