Computer Scheduling [Gelacio]/[Pulan]

#include <iostream>
#include <conio.h>
#include <stdlib.h>
using namespace std;

    struct procs
    {
        int pName =0;
        int arrTime = 0;
        int bTime = 0;
        int wTime=0;
        int tTime=0;
        int eTime=0;
        int sTime=0;
        int iTime=0;
        int prio=0;
    };

void print_gantt_chart(procs P[], int numProc);

int main(procs P[])
{

    int numProc = 0;
    int choice = 0;

top:

    cout<< "Welcome to CPU Scheduling Algorithm, please pick an option.\n[1]First Come First Serve\n[2]Shortest Job First\n[3]Priority"<<endl;
    cout<<"\nOption: ";
    cin>>choice;
    cin.ignore();
    while(!cin)
    {
        cout<<"Invalid Input, Please try again\n";
        cin.clear();
        cin.ignore();
        system("pause");
        system("cls");
        goto top;
    }

    if(choice==1)
    {
        cout<<"\nRedirecting to FCFS"<<endl;
        system("pause");
        system("cls");
        cout<<" ======================"<<endl;
        cout<<"|First Come First Serve|"<<endl;
        cout<<" ======================"<<endl;
    }

    else if(choice==2)
    {
        cout<<"\nRedirecting to SJF"<<endl;
        system("pause");
        system("cls");
        cout<<" =================="<<endl;
        cout<<"|Shortest Job First|"<<endl;
        cout<<" =================="<<endl;
    }

    else if(choice==3)
    {
        cout<<"\nRedirecting to Prio"<<endl;
        system("pause");
        system("cls");
        cout<<" ========"<<endl;
        cout<<"|Priority|"<<endl;
        cout<<" ========"<<endl;
    }

    else
    {
        cout<<"\nInvalid Input, Please try again"<<endl;
        system("pause");
        system("cls");
        goto top;
    }

proc:

    cout << "\nEnter number of processes: ";
    cin>>numProc;
    while(!cin)
    {
        cout<<"Invalid\nEnter number of processes: ";
        cin.clear();
        cin.ignore();
        cin>>numProc;
        cin.ignore();
    }
    if (numProc<=10)
    {

        procs P[numProc];

        for (int i=0; i<numProc;i++)
        {
            P[i].pName = i+1;
            cout << "Process #: "<<P[i].pName<<endl;
            cout << "Arrival Time: ";
            cin >> P[i].arrTime;
            while(!cin)
            {
                cout<<"Invalid\nArrival Time: ";
                cin.clear();
                cin.ignore();
                cin>>P[i].arrTime;
                cin.ignore();
            }

            cout << "Burst Time: ";
            cin >> P[i].bTime;
            while(!cin)
            {
                cout<<"Invalid\nBurst Time: ";
                cin.clear();
                cin.ignore();
                cin>>P[i].bTime;
                cin.ignore();
            }
            if(choice==3)
            {
                cout<<"Priority: ";
                cin>>P[i].prio;
                while(!cin)
                {
                    cout<<"Invalid\nPriority: ";
                    cin.clear();
                    cin.ignore();
                    cin>>P[i].prio;
                    cin.ignore();
                }
            }
            cout<<endl;
        }

    //FCFS Sorting
    for (int j=0; j<numProc-1;j++)
    {
        for (int k=0;k<numProc-j-1;k++)
        {
            if (P[k].arrTime>P[k+1].arrTime)
            {
                swap(P[k].arrTime,P[k+1].arrTime);
                swap(P[k].pName,P[k+1].pName);
                swap(P[k].bTime,P[k+1].bTime);
                swap(P[k].prio,P[k+1].prio);
            }
        }
    }

    //SJF Sorting
    if(choice==2)
    {
        for (int i=0; i<numProc-1;i++)
        {
            for (int j=1;i<numProc-j-1;j++)
            {
                if(P[j].bTime>=P[j+1].bTime)
                {
                    swap(P[j].arrTime,P[j+1].arrTime);
                    swap(P[j].pName,P[j+1].pName);
                    swap(P[j].bTime,P[j+1].bTime);

                }
            }
        }
    }

    else if(choice==3)
    {
        //Prio Sorting

        int p;

        //Same Arrival Time Condition
        for (int i=0; i<numProc-1;i++)
        {
            for (int j=1;j<numProc;j++)
            {
                if(j!=i)
                {
                    if(P[i].arrTime == P[j].arrTime)
                    {
                        p= true;
                    }
                }
            }
        }

        if(p==true)
        {
            for (int i=0; i<numProc-1;i++)
            {
                for (int j=1;j<numProc-i-1;j++)
                {
                    if(P[j].arrTime<=P[j-1].eTime&&P[j].prio>=P[j+1].prio)
                    {
                        swap(P[j].prio,P[j+1].prio);
                        swap(P[j].arrTime,P[j+1].arrTime);
                        swap(P[j].pName,P[j+1].pName);
                        swap(P[j].bTime,P[j+1].bTime);
                    }
                }
            }
        }

        //No same Arrival Time
        else
        {
        for (int i=0; i<numProc-1;i++)
        {
            for (int j=1;i<numProc-j-1;j++)
            {
                if(P[j].bTime>=P[j+1].bTime)
                {
                    swap(P[j].arrTime,P[j+1].arrTime);
                    swap(P[j].pName,P[j+1].pName);
                    swap(P[j].bTime,P[j+1].bTime);
                    swap(P[j].bTime,P[j+1].bTime);
                }
            }
        }
        }

    }

    //Idle Condition
    for (int i =0;i<numProc;i++)
    {
        if(i==0)
        {
            P[0].sTime = P[0].arrTime;
            P[0].eTime = P[0].arrTime + P[0].bTime;
        }
        else
        {
            P[i].sTime = P[i-1].eTime;
            if(P[i].arrTime>P[i].sTime)
            P[i].sTime = P[i].arrTime;
            P[i].eTime = P[i].sTime + P[i].bTime;
        }
    }

    if(choice==1||choice==2)
    {
        cout << "P#\t\tAT\t\tBT\t\tWT\t\tTT\t\t" <<endl;
        for (int l=0; l<numProc;l++)
        {
            cout << P[l].pName<<"\t\t"<<P[l].arrTime<<"\t\t"<<P[l].bTime<<"\t\t"<<P[l].sTime<<"\t\t"<<P[l].eTime<<endl;
        }
    }

    else if(choice==3)
    {
        cout << "P#\t\tAT\t\tBT\t\tWT\t\tTT\t\tP" <<endl;
        for (int j=0; j<numProc;j++)
        {
            cout << P[j].pName<<"\t\t"<<P[j].arrTime<<"\t\t"<<P[j].bTime<<"\t\t"<<P[j].sTime<<"\t\t"<<P[j].eTime<<"\t\t"<<P[j].prio<<endl;
        }
    }

    cout<< "\nGantt Chart" <<endl;
    print_gantt_chart(P,numProc);

    }
    else
    {
        cout <<"Invalid Input! must not be greater than 10"<<endl;
        goto proc;
    }

    system("pause");
    return 0;
}

void print_gantt_chart(procs P[], int numProc)
{
    int i, j;

    cout <<" ";
    for(i=0; i<numProc; i++)
    {
        for(j=0; j<P[i].bTime; j++) cout <<"--";
        cout <<" ";
    }

    cout <<"\n|";

    for(i=0; i<numProc; i++) {
        for(j=0; j<P[i].bTime - 1; j++) cout <<" ";
        cout<<P[i].pName;
        for(j=0; j<P[i].bTime - 1; j++) cout<< " ";
        cout<<" |";
    }
    cout<<"\n ";

    for(i=0; i<numProc; i++) {
        for(j=0; j<P[i].bTime; j++) cout<<"--";
        cout<<" ";
    }
    cout<<"\n";
    int diffindex = P[0].sTime - 0;
    int diff = 0;
    int hold = 0;

    if (diffindex==0)
    cout<<"0";
    else
    cout<<"0"<<"[I]"<< 0+diffindex;
    for(i=0; i<numProc; i++)
    {   hold=0;
        if (i<3)
        diff = P[i+1].sTime - P[i].eTime;
        if (diff!=0)
        {
            hold = 1;
        }


        if (hold==1)
        {
            for(j=0; j<P[i].bTime-2; j++) cout<<"  ";
            cout<<P[i].eTime<< "[I]"<<P[i].eTime+diff;
        }
        else
        {
            for(j=0; j<P[i].bTime-1; j++) cout<<"  ";
         cout<<P[i].eTime<<"";

        }

    }
    cout<<"\n";

}