kaoru78, you need to learn how to ask nicely. Here are some suggestions:
- Pick the right forum. This looks like homework to me.
- Use a decent subject. "pleasee help me..." doesn't help me understand what this thread is about.
- Tell us the story of what you have tried, what parts you are having trouble with, what your plan is to solve the problem, etc. That way we can know what exactly to help you with.
- What is the Drozdek/lecture version to indicate shortest paths? You should give us the material required to understand your question.
Then I'll consider answering.