Compilare: user.cpp: In function ‘int main()’: user.cpp:38:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < numbers.size(); i++) ^ user.cpp:30:8: warning: unused variable ‘res’ [-Wunused-variable] int x,res = 0; ^ user.cpp:61:12: warning: ‘sol’ may be used uninitialized in this function [-Wmaybe-uninitialized] out << sol; ^