thanks billionsCode:cout<<"Enter Filename for input e.g(inp1.txt .... inp10.txt):"<<flush; cin>>filename; ifstream inpfile; inpfile.open(filename,ios::in); if(inpfile.is_open()) { inpfile>>width; inpfile>>height; } else { cout<<"invalid file"<<endl; } std::vector<Cell> row; for (int i = 0; i < livingCells.size(); i++) { inpfile.getline(board,255); livingCells.push_back(row); }