FCFS & SJF

#include <iostream>

using namespace std;

struct Process {
    int pid;
    int arrival_time;
    int burst_time;
    int start_time;
    int finish_time;
    int turnaround_time;
    int waiting_time;
};

void fcfs(Process [], int);
void sjf(Process [], int);
void printTable(Process [], int);

int main() {
    int n;
    cout << "Enter the number of processes: ";
    cin >> n;

    Process proc[n];
    for (int i = 0; i < n; i++) {
        cout << "Enter arrival time and burst time for process " << i + 1 << ": ";
        cin >> proc[i].arrival_time >> proc[i].burst_time;
        proc[i].pid = i + 1;
    }

    cout << "\nFCFS Scheduling:\n";
    fcfs(proc, n);
    printTable(proc, n);

    cout << "\nSJF Scheduling:\n";
    sjf(proc, n);
    printTable(proc, n);

    return 0;
}

void fcfs(Process proc[], int n) {
    int time = 0;
    for (int i = 0; i < n; i++) {
        if (time < proc[i].arrival_time) {
            time = proc[i].arrival_time;
        }
        proc[i].start_time = time;
        time += proc[i].burst_time;
        proc[i].finish_time = time;
        proc[i].turnaround_time = proc[i].finish_time - proc[i].arrival_time;
        proc[i].waiting_time = proc[i].turnaround_time - proc[i].burst_time;
    }
}

void sjf(Process proc[], int n) {
    int time = 0, completed = 0;
    while (completed != n) {
        int shortest = INT_MAX, index = -1;
        for (int i = 0; i < n; i++) {
            if (proc[i].arrival_time <= time && proc[i].burst_time >= 0 && proc[i].burst_time < shortest) {
                shortest = proc[i].burst_time;
                index = i;
            }
        }

        if (index != -1) {
            proc[index].start_time = time;
            time += proc[index].burst_time;
            proc[index].finish_time = time;
            proc[index].turnaround_time = proc[index].finish_time - proc[index].arrival_time;
            proc[index].waiting_time = proc[index].turnaround_time - proc[index].burst_time;
            proc[index].burst_time = 0;
            completed++;
        } else {
            time++;
        }
    }
}

void printTable(Process proc[], int n) {
    cout << "Process ID\tArrival Time\tBurst Time\tStart Time\tFinish Time\tTurnaround Time\tWaiting Time\n";
    for (int i = 0; i < n; i++) {
        cout << proc[i].pid << "\t\t" << proc[i].arrival_time << "\t\t" << proc[i].burst_time << "\t\t" << proc[i].start_time << "\t\t" << proc[i].finish_time << "\t\t" << proc[i].turnaround_time << "\t\t" << proc[i].waiting_time << "\n";
    }
}