Practical 1: Write a program to simulate CPU Scheduling Algorithms: FCFS, SJF
(Preemptive), Priority (Non-Preemptive) and Round Robin (Preemptive).
ROUND ROBIN:
#include<stdio.h>
int main() {
int i, j, n, bu[10], wa[10], tat[10], t, ct[10], max;
float awt = 0, att = 0, temp = 0;
printf("Onkar lonsane Roll No = 28");
printf("\nEnter the number of processes: ");
scanf("%d", &n);
// Input burst times for each process
for(i = 0; i < n; i++) {
printf("Enter Burst Time for Process %d: ", i + 1);
scanf("%d", &bu[i]);
ct[i] = bu[i]; // Copy burst time to ct array for later calculations
}
printf("Enter the size of time slice: ");
scanf("%d", &t);
max = bu[0];
for(i = 1; i < n; i++) {
if(max < bu[i])
max = bu[i];
}
// Round Robin Scheduling logic
for(j = 0; j < (max / t) + 1; j++) {
for(i = 0; i < n; i++) {
if(bu[i] != 0) {
if(bu[i] <= t) {
tat[i] = temp + bu[i];
temp = temp + bu[i];
bu[i] = 0;
} else {
bu[i] = bu[i] - t;
temp = temp + t;
}
}
}
}
// Calculate waiting time and turnaround time for each process
for(i = 0; i < n; i++) {
wa[i] = tat[i] - ct[i];
att += tat[i];
awt += wa[i];
}
// Print Average Turnaround Time and Average Waiting Time
printf("\nAverage Turnaround Time: %.2f", att / n);
printf("\nAverage Waiting Time: %.2f\n", awt / n);
// Display process details
printf("\nPROCESS\t BURST TIME \t WAITING TIME\t TURNAROUND TIME\n");
for(i = 0; i < n; i++) {
printf("%d\t %d\t\t %d\t\t %d\n", i + 1, ct[i], wa[i], tat[i]);
}
return 0;
}
Output:
/tmp/cLPP1KUzvE.o
Onkar lonsane Roll No = 28
Enter the number of processes: 2
Enter Burst Time for Process 1: 4
Enter Burst Time for Process 2: 6
Enter the size of time slice: 2
Average Turnaround Time: 8.00
Average Waiting Time: 3.00
PROCESS BURST TIME WAITING TIME TURNAROUND TIME
1 4 2 6
2 6 4 10
=== Code Execution Successful ===
