Disk Scheduling algorithms, calculate average seek time

Write a program to calculate average seek time for a few disk scheduling algorithms: FCFS (first come first served), SSF (shortest seek first), Elevator, CSCAN. Your program will accept a parameter N (number of requests in buffer; how many requests are being compared to determine which one to do next). The input into your program is a stream of numbers indicating where to seek to. The output is just a an average seek time (or 4 averages if you decide to do all 4 algorithms in a single program).