2.Write a python program to demonstrate SJF scheduling Algorithm.

 

def main():
	# Taking the number of processes
	n = int(input("Enter number of process: "))
	
	A = [[0 for j in range(4)] for i in range(100)]
	total, avg_wt, avg_tat = 0, 0, 0
	print("Enter Burst Time:")
	for i in range(n): 
		A[i][1] = int(input(f"P{i+1}: "))
		A[i][0] = i + 1
	for i in range(n): 
		index = i
		for j in range(i + 1, n):
			if A[j][1] < A[index][1]:
				index = j
		temp = A[i][1]
		A[i][1] = A[index][1]
		A[index][1] = temp
		temp = A[i][0]
		A[i][0] = A[index][0]
		A[index][0] = temp
	A[0][2] = 0
	for i in range(1, n):
		A[i][2] = 0
		for j in range(i):
			A[i][2] += A[j][1]
		total += A[i][2]
	avg_wt = total / n
	total = 0
	
	print("P	 BT	 WT	 TAT")
	for i in range(n):
		A[i][3] = A[i][1] + A[i][2]
		total += A[i][3]
		print(f"P{A[i][0]}	 {A[i][1]}	 {A[i][2]}	 {A[i][3]}")
	avg_tat = total / n
	print(f"Average Waiting Time= {avg_wt}")
	print(f"Average Turnaround Time= {avg_tat}")


if __name__ == "__main__":
	main()




Output b2:
Enter total number of processes(maximum 20): 3

Enter Process Burst Time
P[1]: 2
P[2]: 1
P[3]: 4

Average Turnaround Time: 4.0ms

Average Waiting Time: 1.6666666666666667ms

Process	Burst Time	Waiting Time	Turnaround Time
P[1]	2		0		2
P[2]	1		2		3
P[3]	4		3		7