C++ program to implement FCFS CPU scheduling algorithm

C++ program to implement First Come First Serve CPU scheduling algorithm.

C++ program to implement FCFS CPU scheduling algorithm without arrival time

#include<iostream>
#include<iomanip>
using namespace std;
class fcfs_alg
{
    int exe[10];
    int n;
public:
    void getdata();
    void display();
    void cal_wt_tt();
};
void fcfs_alg::getdata()
{
    cout<<"How many process to be entered : ";
    cin>>n;
    for(int i=0;i<n;i++)
    {
        cout<<"Enter execution time of process "<<i+1<<" : ";
        cin>>exe[i];
    }
}
void fcfs_alg::display()
{
    cout<<endl<<"Process ID\tExecution time\tArrival Time "<<endl;
    for(int i=0;i<n;i++)
        cout<<setw(5)<<i+1<<setw(15)<<exe[i]<<setw(15)<<"0"<<endl;
}
void fcfs_alg::cal_wt_tt()
{
    int wt=0,tnt=0;
float avg=0,avtnt=0;
    cout<<"\nProcess id \tWaiting time \tTurn around time "<<endl;
    for(int i=0;i<n;i++)
    {
        tnt+=exe[i];
        avtnt+=tnt;
        avg+=wt;
        cout<<setw(5)<<i+1<<setw(15)<<wt<<setw(15)<<tnt<<endl;
        wt+=exe[i];
    }
    avg=avg/(float)n;
    avtnt/=(float)n;
    cout<<"\nAverage Waiting time     : "<<avg;
    cout<<"\nAverage turn Around time : "<<avtnt<<endl;
}
int main()
{
fcfs_alg fcfs;
fcfs.getdata();
fcfs.display();
fcfs.cal_wt_tt();
    return 0;
}

OUTPUT

C++ program to implement FCFS CPU scheduling algorithm with arrival time

#include<iostream>
#include<iomanip>
using namespace std;
class fcfs_alg
{
    int ar[10],exe[10],id[10];
    int n;
    void sort(int *,int *,int *);
public:
    void getdata();
    void display();
    void cal_wt_tt();
};
void fcfs_alg::getdata()
{
    cout<<"How many process to be entered : ";
    cin>>n;
    for(int i=0;i<n;i++)
    {
        cout<<"Enter execution time and arrival time of process "<<i+1<<" : ";
        cin>>exe[i]>>ar[i];
        id[i]=i+1;
    }
}
void fcfs_alg::display()
{
    cout<<endl<<"Process ID\tExecution time\tArrival Time "<<endl;
    for(int i=0;i<n;i++)
        cout<<setw(5)<<i+1<<setw(15)<<exe[i]<<setw(15)<<ar[i]<<endl;
}
void fcfs_alg::sort(int *f,int *m,int *l)
{
    int temp;
    for(int y=0;y<n-1;y++)
    {
        for(int z=0;z<n-1;z++)
            if(f[z]>f[z+1])
            {
                temp=f[z];
                f[z]=f[z+1];
                f[z+1]=temp;
                temp=l[z];
                l[z]=l[z+1];
                l[z+1]=temp;
                temp=m[z];
                m[z]=m[z+1];
                m[z+1]=temp;
            }
    }
}
void fcfs_alg::cal_wt_tt()
{
    int wt,tnt,temp;
float avg=0,avtnt=0;
    sort(ar,exe,id);
    temp=ar[0];
    cout<<"\nProcess id \tWaiting time \tTurn around time "<<endl;
    for(int i=0;i<n;i++)
    {
        if(ar[i]>temp)
        {
            wt=0;
            temp=ar[i];
        }
        else
            wt=temp-ar[i];
        avg+=wt;
        temp+=exe[i];
        tnt=temp-ar[i];
        avtnt+=tnt;
        cout<<setw(5)<<id[i]<<setw(15)<<wt<<setw(15)<<tnt<<endl;
    }
    avg=avg/(float)n;
    avtnt/=(float)n;
    cout<<"\nAverage Waiting time     : "<<avg;
    cout<<"\nAverage turn Around time : "<<avtnt<<endl;
}
int main()
{
fcfs_alg fcfs;
fcfs.getdata();
fcfs.display();
fcfs.cal_wt_tt();
    return 0;
}

OUTPUT

C++ program to implement FCFS CPU scheduling algorithm with Gantt chart

Following program uses BGI graphics and compiled it using TurboC/C++ 3.0 compiler.

#include<iostream.h>
#include<graphics.h>
#include<iomanip.h>
#include<conio.h>
#include<string.h>
class fcfs_alg
{
    int ar[10],exe[10],id[10];
    char d[10];
    int n,x,y;
    void sort(int *,int *,int *);
public:
    void getdata();
    void display();
    void chart(int,int);
    void int_to_ch(int);
    void cal_wt_tt();
};
void fcfs_alg::getdata()
{
    cout<<"How many process to be entered : ";
    cin>>n;
    for(int i=0;i<n;i++)
    {
cout<<"Enter execution time and arrival time of process "<<i+1<<" : ";
cin>>exe[i]>>ar[i];
id[i]=i+1;
    }
}
void fcfs_alg::int_to_ch(int temp)
{
   int i;
   if(temp==0)
   {
      d[0]=48;
      d[1]=0;
      return;
   }
   for(i=0;temp!=0;i++)
    {
d[i]=temp%10+48;
temp/=10;
    }
    d[i]=0;
    strrev(d);
}
void fcfs_alg::chart(int id,int t)
{
    rectangle(x,y,x+30,y+30);
    if(id!=-1)
    {
       int_to_ch(id);
       outtextxy(x+12,y+12,d);
    }
    int_to_ch(t);
    if(t>10)
       outtextxy(x+24,y+33,d);
    else
       outtextxy(x+30,y+33,d);
    x+=30;
    if(x+60>getmaxx())
    {
       y+=50;
       x=5;
       outtextxy(x,y+33,d);
    }
}
void fcfs_alg::display()
{
    int gdriver = DETECT, gmode;
    initgraph(&gdriver, &gmode, "");
    outtextxy(5,56,"Process ID    Execution time   Arrival Time ");
    x=5,y=66;
    for(int i=0;i<n;i++,y+=16)
    {
int_to_ch(i+1);
outtextxy(35,y,d);
int_to_ch(exe[i]);
outtextxy(150,y,d);
int_to_ch(ar[i]);
outtextxy(270,y,d);
    }
}
void fcfs_alg::sort(int *f,int *m,int *l)
{
    int temp;
    for(int y=0;y<n-1;y++)
    {
for(int z=0;z<n-1;z++)
   if(f[z]>f[z+1])
   {
temp=f[z];
f[z]=f[z+1];
f[z+1]=temp;
temp=l[z];
l[z]=l[z+1];
l[z+1]=temp;
temp=m[z];
m[z]=m[z+1];
m[z+1]=temp;
   }
    }
}
void fcfs_alg::cal_wt_tt()
{
    int wt,tnt,temp,z=y+10;
    float avg=0,avtnt=0;
    sort(ar,exe,id);
    temp=ar[0];
    y+=(n+2)*16;
    outtextxy(x,y+10,"GANTT CHART");
    y=y+26;
    int_to_ch(temp);
    outtextxy(x,y+33,d);
    outtextxy(x,z,"Process id    Waiting time    Turn around time ");
    z=z+16;
    for(int i=0;i<n;i++,z+=16)
    {
if(ar[i]>temp)
{
   wt=0;
   temp=ar[i];
   chart(-1,temp);
}
else
   wt=temp-ar[i];
avg+=wt;
temp+=exe[i];
tnt=temp-ar[i];
avtnt+=tnt;
int_to_ch(id[i]);
outtextxy(35,z,d);
int_to_ch(wt);
outtextxy(150,z,d);
int_to_ch(tnt);
outtextxy(270,z,d);
chart(id[i],temp);
    }
    avg=avg/(float)n;
    avtnt/=(float)n;
    cout<<"\nAverage Waiting time     : "<<avg;
    cout<<"\nAverage turn Around time : "<<avtnt<<endl;
}
int main()
{
    fcfs_alg fcfs;
    fcfs.getdata();
    fcfs.display();
    fcfs.cal_wt_tt();
    getch();
    return 0;
}

OUTPUT