For this computer assignment, you are to write a C++ program to implement several graph algorithms on simple graphs. These graphs are implemented with adjacency list representation. The `graph` class is already defined in the header file `assignment09.h` and included as part of this repository.9.cc. You can insert new code to both files, including data members to the header file if necessary. Usually the source file (.cc) contains the implementation of member methods of the class. You can add inline code in the header file (.h) when the implementation is very brief, containing just one or two lines for a member method.
