std::vector<std::vector<StackBlock*> > EndlessMode::VVMainGrid = std::vector<std::vector<StackBlock*> >(_COLUMN_SIZE, std::vector<StackBlock*>(_ROW_SIZE, nullptr));
std::vector<int> EndlessMode::VIColumnWeight = std::vector<int>(_COLUMN_SIZE, 0);
std::vector<int> EndlessMode::VIRowWeight = std::vector<int>(_ROW_SIZE, 0);