White Box Testing Using Control Flow Graph?

How to Write Test Cases in White Box Testing Using Control Flow graph Technique?!

Hi, i have a code written in C++ language, and i drew the Control flow graph to do path testing which it is 4 paths, BUT, if you may help me guys to first check my answer whether it's right or not, and explain how can i write the right Test Cases for it, i tried and search for the solution but still i didn't get it perfectly.. i would appreciate it if you explain the solution in details .... ?! see attached pic for the code and the graph.

the code + control flow graph