SJF added. FCFS modified and renamed to non_preemptive. Its new generic for FCFS and SJF
SJF added. FCFS modified and renamed to non_preemptive. Its new generic for FCFS and SJF

ashgkwd/college-practs,ashgkwd/college-practs,ashgkwd/college-practs,ashgkwd/college-practs,ashgkwd/college-practs,ashgkwd/college-practs