7.Write a program to implement round robin scheduling algorithm.

Write a program to implement round robin scheduling algorithm.


#include<iostream>
using namespace std;
class sched
{
public:
int n,bt[10],at[10],tat[10],wt[10],rt[10],finish[10],twt,ttat,total;
void readData();
void Init();
void dispTime();
void computeRR();
};

void sched::readData()
{
cout<<"Enter no. of processes\n";
cin>>n;
cout<<"Enter the burst times in order :\n";
for(int i=0;i<n;i++)
cin>>bt[i];
cout<<"Enter the arrival times in order:\n";
for(int i=0;i<n;i++)
cin>>at[i];
}

void sched::Init()
{
total=0;
twt=0;
ttat=0;
for(int i=0; i<n; i++)
{
rt[i]=bt[i];
finish[i]=0;
wt[i]=0;
tat[i]=0;
total+=bt[i];
}
}

void sched::dispTime()
{
for(int i=0;i<n;i++)
{
twt+=wt[i];
tat[i]=wt[i]+bt[i];
ttat+=tat[i];
cout<<"Waiting time for P"<<(i+1)<<" = "<<wt[i]<<", Turnaround time = "<<tat[i]<<endl;
}

cout<<"Avg Waiting time = "<<(double)twt/n<<" and Avg Turnaround time = "<<(double)ttat/n<<endl;
cout<<"Scheduling complete\n";
}

void sched::computeRR(){
readData();
Init();
int time,j,q,i,dec=0;
cout<<"Enter the time quantum:\n";
cin>>q;
cout<<"Gantt Chart\n ";
for(time=0;time<total;)
{
for(i=0;i<n;i++)
{
if(at[i]<=time && finish[i]==0)
{
cout<<"("<<time<<")|==P"<<(i+1)<<"==|";
if(rt[i]<q)  {
dec=rt[i];
}
else {dec=q;}
rt[i]=rt[i]-dec;
if(rt[i]==0)
finish[i]=1;
for(j=0;j<n;j++)
if(j!=i && finish[j]==0 && at[j]<=time)
wt[j]+=dec;
time=time+dec;
}
}
}
cout<<"("<<total<<")"<<endl;
dispTime();
}
int main()
{
sched t;
int ch;
t.computeRR();
}

Output: