SystemsProgrammingAndOperatingSystem/Codes/Group B/Assignment - 5/SJF (Preemptive).cpp

#include <iostream>
using namespace std;

struct sjf{
    int id, arr, bur, comp, turn, wait, orgBur;
};
sjf meh[30];

class SJF{
public:
    int n;
    void getIn()
    {
        cout<<"Enter number of processes: ";
        cin>>n;
        for(int i = 0; i < n; i++){
            cout<<"\nEnter arrival time for process "<<i<<": ";
            cin>>meh[i].arr;
            cout<<"Enter burst time for process "<<i<<": ";
            cin>>meh[i].bur;
            meh[i].orgBur = meh[i].bur;
            meh[i].id = i;
        }
    }

    void process()
    {
        int k = 0;
        int completed = 0;
        cout<<"\nSequence of processes is: ";
        while(completed < n){
            int burst = 999;
            int idd = -1;
            for(int i = 0; i < n; i++){
                if(meh[i].arr <= k && meh[i].bur > 0){
                    if(meh[i].bur < burst){
                        burst = meh[i].bur;
                        idd = i;
                    }
                }
            }
            if(idd != -1){
                cout<<"P"<<idd<<" ";
                k++;
                meh[idd].bur--;
                if(meh[idd].bur == 0){
                    meh[idd].comp = k;
                    meh[idd].turn = meh[idd].comp - meh[idd].arr;
                    meh[idd].wait = meh[idd].turn - meh[idd].orgBur;
                    completed++;
                }
            } else{
                k++;
            }
        }
    }

    void display()
    {
        double turn = 0, comp = 0, wait = 0;
        cout<<"\n     Completed | Waiting | Turnaround |";
        for(int i = 0; i < n; i++){
            turn += meh[i].turn;
            wait += meh[i].wait;
            comp += meh[i].comp;
            cout<<"\nP"<<i<<"|  "<<meh[i].comp<<"  |  "<<meh[i].wait<<"  |  "<<meh[i].turn;
        }

        cout<<"\n\nAvg completion time: "<<comp/n;
        cout<<"\nAvg turnaround time: "<<turn/n;
        cout<<"\nAvg waiting time: "<<wait/n;
    }
};

int main()
{
    SJF ob;
    ob.getIn();
    ob.process();
    ob.display();
    return 0;
}