fcfs.c

#include<stdio.h>
 
struct process {
    int pid;      
    int burst;   
    int waiting;  
    int turnaround;
};
 
void calculateTimes(struct process proc[], int n) {
    int total_waiting = 0, total_turnaround = 0;
   
    proc[0].waiting = 0;
    
    proc[0].turnaround = proc[0].burst;
 
    for (int i = 1; i < n; i++) {
        proc[i].waiting = proc[i - 1].waiting + proc[i - 1].burst;
        proc[i].turnaround = proc[i].waiting + proc[i].burst;
    }
}
 
void displayProcesses(struct process proc[], int n) {
    printf("Process ID\tBurst Time\tWaiting Time\tTurnaround Time\n");
    for (int i = 0; i < n; i++) {
        printf("%d\t\t%d\t\t%d\t\t%d\n", proc[i].pid, proc[i].burst, proc[i].waiting, proc[i].turnaround);
    }
}
 
void calculateAverages(struct process proc[], int n, float *avg_waiting, float *avg_turnaround) {
    int total_waiting = 0, total_turnaround = 0;
    for (int i = 0; i < n; i++) {
        total_waiting += proc[i].waiting;
        total_turnaround += proc[i].turnaround;
    }
    *avg_waiting = (float)total_waiting / n;
    *avg_turnaround = (float)total_turnaround / n;
}
 
int main() {
    int n; 
    printf("Enter the number of processes: ");
    scanf("%d", &n);
    struct process proc[n]; 
    printf("Enter the burst time for each process:\n");
    for (int i = 0; i < n; i++) {
        proc[i].pid = i + 1;
        printf("Process %d: ", i + 1);
        scanf("%d", &proc[i].burst);
    }
    calculateTimes(proc, n);
    displayProcesses(proc, n);
    float avg_waiting, avg_turnaround;
    calculateAverages(proc, n, &avg_waiting, &avg_turnaround);
    printf("\nAverage Waiting Time: %.2f\n", avg_waiting);
    printf("Average Turnaround Time: %.2f\n", avg_turnaround);
 
    return 0;
}




Output:

Enter the number of processes: 4
Enter the burst time for each process:
Process 1: 1
Process 2: 2
Process 3: 3
Process 4: 4
Process ID	Burst Time	Waiting Time	Turnaround Time
1		1		0		1
2		2		1		3
3		3		3		6
4		4		6		10

Average Waiting Time: 2.50
Average Turnaround Time: 5.00