C++ program to implement Round Robin CPU scheduling algorithm

C++ program to implement Round Robin CPU scheduling algorithm.

C++ program to implement Round Robin CPU scheduling algorithm without arrival time

#include<iostream>
#include<iomanip>
using namespace std;
class rr_alg
{
    int exe[10];
    int n,q;
public:
    void getdata();
    void display();
    void cal_wt_tt();
};
void rr_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];
    }
    cout<<"Enter Quantum slice : ";
cin>>q;
}
void rr_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 rr_alg::cal_wt_tt()
{
    int texe=0,exe2[10],flag=1;
int wt=0,tnt=0;
float avg=0,avtnt=0;
for(int i=0;i<n;i++)
{
   texe+=exe[i];
   exe2[i]=exe[i];
}
cout<<"\nProcess ID \tWaiting time \tTurn Around time "<<endl;
for(int y=0;y<texe;y++)
    {
        for(int i=0;i<n;i++)
        {
            if(exe[i]<=0)
                continue;
   tnt+=q;
   exe[i]-=q;
       if(exe[i]<=0)
       {
           tnt+=exe[i];
           wt=tnt-exe2[i];
       cout<<setw(5)<<i+1<<setw(15)<<wt<<setw(15)<<tnt<<endl;
       avg+=wt;
       avtnt+=tnt;
       }
        }
    }
    avg=avg/(float)n;
    avtnt/=(float)n;
    cout<<"\nAverage Waiting time     : "<<avg;
    cout<<"\nAverage turn Around time : "<<avtnt<<endl;
}
int main()
{
rr_alg rr;
rr.getdata();
rr.display();
rr.cal_wt_tt();
    return 0;
}

OUTPUT

C++ program to implement Round Robin CPU scheduling algorithm with arrival time

#include<iostream>
#include<iomanip>
using namespace std;
class rr_alg
{
    int ar[10],id[10],exe[10];
    int n,q;
    void sort(int *f,int *mid,int *last);
public:
    void getdata();
    void display();
    void cal_wt_tt();
};
void rr_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;
    }
    cout<<"Enter Quantum slice : ";
cin>>q;
}
void rr_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 rr_alg::sort(int *f,int *mid,int *last)
{
    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=mid[z];
                mid[z]=mid[z+1];
                mid[z+1]=temp;
                temp=last[z];
                last[z]=last[z+1];
                last[z+1]=temp;
            }
    }
}

void rr_alg::cal_wt_tt()
{
    int exe2[10],flag=1,flag1=0;
int at=0,wt,tnt;
float avg=0,avtnt=0;
sort(ar,id,exe);
for(int i=0;i<n;i++)
   exe2[i]=exe[i];
    at=ar[0];
cout<<"\nProcess ID \tWaiting time \tTurn Around time "<<endl;
while(flag)
    {
        for(int i=0;i<n;i++)
        {
            if(at<ar[i]||id[i]<0)
                continue;
            flag1=1;
   at+=q;
   exe[i]-=q;
       if(exe[i]<=0)
       {
           at+=exe[i];
           wt=at-exe2[i]-ar[i];
       tnt=at-ar[i];
       cout<<setw(5)<<id[i]<<setw(15)<<wt<<setw(15)<<tnt<<endl;
       id[i]=-1;
       avg+=wt;
       avtnt+=tnt;
       }
        }
        if(flag1==0)
            at++;
        flag1=flag=0;
        for(int k=0;k<n;k++)
            if(id[k]!=-1)
               flag=1;
    }
    avg=avg/(float)n;
    avtnt/=(float)n;
    cout<<"\nAverage Waiting time     : "<<avg;
    cout<<"\nAverage turn Around time : "<<avtnt<<endl;
}
int main()
{
rr_alg rr;
rr.getdata();
rr.display();
rr.cal_wt_tt();
    return 0;
}

OUTPUT

C++ program to implement Round Robin CPU scheduling algorithm with Gantt chart

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

#include<graphics.h>
#include<iomanip.h>
#include<conio.h>
#include<string.h>
class rr_alg
{
    int ar[10],id[10],exe[10];
    int n,q,x,y;
    char d[10];
    void sort(int *f,int *mid,int *last);
public:
    void getdata();
    void display();
    void cal_wt_tt();
    void int_to_ch(int);
    void chart(int,int);
};
void rr_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;
    }
    cout<<"Enter Quantum slice : ";
cin>>q;
}
void rr_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 rr_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 rr_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 rr_alg::sort(int *f,int *mid,int *last)
{
    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=mid[z];
mid[z]=mid[z+1];
mid[z+1]=temp;
temp=last[z];
last[z]=last[z+1];
last[z+1]=temp;
   }
    }
}
void rr_alg::cal_wt_tt()
{
    int exe2[10],flag=1,flag1=0,fl=1;
    int at=0,wt,tnt,z=y+10,prev,ap;
    float avg=0,avtnt=0;
    sort(ar,id,exe);
    for(int i=0;i<n;i++)
exe2[i]=exe[i];
    at=ar[0];
    y+=(n+2)*16;
    outtextxy(x,y+10,"GANTT CHART");
    y=y+26;
    int_to_ch(at);
    outtextxy(x,y+33,d);
    outtextxy(x,z,"Process id    Waiting time    Turn around time ");
    z=z+16;
    while(flag)
    {
for(int i=0;i<n;i++)
{
   if(at<ar[i]||id[i]<0)
continue;
   if(fl==0)
      chart(-1,at);
   fl=flag1=1;
   at+=q;
   exe[i]-=q;
   if(exe[i]<0)
at+=exe[i];
   chart(id[i],at);
   if(exe[i]<=0)
   {
wt=at-exe2[i]-ar[i];
tnt=at-ar[i];
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);
z+=16;
id[i]=-1;
avg+=wt;
avtnt+=tnt;
   }
}
if(flag1==0)
{
  at++;
  fl=0;
}
flag1=flag=0;
for(int k=0;k<n;k++)
   if(id[k]!=-1)
      flag=1;
    }
    avg=avg/(float)n;
    avtnt/=(float)n;
    cout<<"\nAverage Waiting time     : "<<avg;
    cout<<"\nAverage turn Around time : "<<avtnt<<endl;
}
int main()
{
    rr_alg rr;
    rr.getdata();
    rr.display();
    rr.cal_wt_tt();
    getch();
    return 0;
}

OUTPUT