Hello,
I am a student of Software Engineer course waiting for graduation, therefore I can offer you not only the best service in algorithm, but also nice cost. I have check the code fragment you posted and would gladly cooperate with you.
Please check my profile for more information, and I also received good feedback from previoous contractor, because I only receive full payment after the customer is satisfied with the product.
And please contact me (using Freelancer private message) to discuss about the price, I can offer lower cost, but as you gave minimum of $15, I cannot enter smaller amount.