Compilare: user.cpp: In function ‘void bk(std::vector<long long int>)’: user.cpp:55:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<fv.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:80:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%lld",&n); ^ user.cpp:87:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%lld%lld",&A,&y); ^