Compilare: user.cpp: In function ‘int main()’: user.cpp:32:47: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘std::vector<long int>::size_type {aka unsigned int}’ [-Wformat=] printf ( "%ld\n", mutualElements.size ( ) ); ^ user.cpp:33:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( long i = 0; i < mutualElements.size ( ); i++ ) ^