To run NORMAL C++ Code (OOP) :

1. g++ filename.cpp
2. ./a.out

To run normal GRAPHICS Code :

1. g++ filename.cpp -lgraph
2. ./a.out

To run OPENGL Code :

1. g++ filename.cpp -lGL -lGLU -lglut
2. ./a.out

NOTE : if g++ is NOT working, try replacing with gcc. NOTE : -o flag followed by outputfilename.out can be used after compiling command for diffrent output file, but will change the output file name required while running also.