Compilare: user.cpp: In function ‘void solve_for(std::vector<short int>&, int)’: user.cpp:76:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); i++) ^ user.cpp:83:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:92:10: warning: unused variable ‘str’ [-Wunused-variable] char str[N]; ^