FCFS Program in C

#include <stdio.h>

struct Process {
    int id;        // Process ID
    int arrival;   // Arrival time
    int burst;     // Burst time
    int waiting;   // Waiting time
    int turnaround; // Turnaround time
};

// Function to calculate waiting time and turnaround time for each process
void calculateTimes(struct Process processes[], int n) {
    int total_waiting = 0;
    int total_turnaround = 0;

    // First process has 0 waiting time
    processes[0].waiting = 0;
    processes[0].turnaround = processes[0].burst;

    for (int i = 1; i < n; i++) {
        // Waiting time for the current process is the turnaround time of the previous process
        processes[i].waiting = processes[i - 1].turnaround;

        // Turnaround time for the current process is waiting time + burst time
        processes[i].turnaround = processes[i].waiting + processes[i].burst;

        total_waiting += processes[i].waiting;
        total_turnaround += processes[i].turnaround;
    }

    // Calculate average waiting time and average turnaround time
    double avg_waiting = (double)total_waiting / n;
    double avg_turnaround = (double)total_turnaround / n;

    // Print the results
    printf("Process\tArrival Time\tBurst Time\tWaiting Time\tTurnaround Time\n");
    for (int i = 0; i < n; i++) {
        printf("%d\t%d\t\t%d\t\t%d\t\t%d\n", processes[i].id, processes[i].arrival, processes[i].burst, processes[i].waiting, processes[i].turnaround);
    }

    printf("Average Waiting Time: %.2lf\n", avg_waiting);
    printf("Average Turnaround Time: %.2lf\n", avg_turnaround);
}

int main() {
    int n; // Number of processes
    printf("Enter the number of processes: ");
    scanf("%d", &n);

    struct Process processes[n];

    // Input process details
    for (int i = 0; i < n; i++) {
        processes[i].id = i + 1;
        printf("Enter Arrival Time for Process %d: ", i + 1);
        scanf("%d", &processes[i].arrival);
        printf("Enter Burst Time for Process %d: ", i + 1);
        scanf("%d", &processes[i].burst);
    }

    // Sort processes based on arrival time (FCFS)
    for (int i = 0; i < n - 1; i++) {
        for (int j = 0; j < n - i - 1; j++) {
            if (processes[j].arrival > processes[j + 1].arrival) {
                struct Process temp = processes[j];
                processes[j] = processes[j + 1];
                processes[j + 1] = temp;
            }
        }
    }

    // Calculate waiting time and turnaround time
    calculateTimes(processes, n);

    return 0;
}