Question

Develop an algorithm and implement Multilevel Queuing scheduling using C++.and using bubble sorting.

Consider a set of user and system processes and determine (i) turnaround time (ii) waiting time of each process (iii) Average Waiting Time (AWT) and (iv) Average Turnaround Time (ATAT) of all processes.

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Answer 1

Code:
#include <iostream>
#include <bits/stdc++.h>
using namespace std;

#define tprocess 4

// create a struct

struct process
{
int Process_no,arrivaltime,bursttime,pr;
};

process proc[50];

bool comp(process A,process B)
{
if(A.arrivaltime == B.arrivaltime)
{
return A.pr<B.pr;
}
else
{
return A.arrivaltime<B.arrivaltime;
}
}

void get_wt_time(int wt[])
{
// service array that contains cumulative burst time
int service[50];

// Initilising elements of the arrays
service[0] = proc[0].arrivaltime;
wt[0]=0;

for(int i=1;i<tprocess;i++)
{
service[i]=proc[i-1].bursttime+service[i-1];

wt[i]=service[i]-proc[i].arrivaltime;

   if(wt[i]<0)
   {
   wt[i]=0;
   }
}

}

void get_tat_time(int tat[],int wt[])
{

for(int i=0;i<tprocess;i++)
{
   tat[i]=proc[i].bursttime+wt[i];
}
  
}

void findtime()
{
//Declare array for waiting time and turnaround time
int wt[50],tat[50];

double wavg=0,tavg=0;

// Function call for waiting time array
get_wt_time(wt);
//Function call for turnaround time
get_tat_time(tat,wt);
  
int stime[50],ctime[50];

stime[0] = proc[0].arrivaltime;
ctime[0]=stime[0]+tat[0];

// calculating starting and ending time
for(int i=1;i<tprocess;i++)
   {
       stime[i]=ctime[i-1];
       ctime[i]=stime[i]+tat[i]-wt[i];
   }
  
cout<<"Process_no\tStart_time\tComplete_time\tTurn_Around_Time\tWaiting_Time"<<endl;
  
  
for(int i=0;i<tprocess;i++)
   {
       wavg += wt[i];
       tavg += tat[i];
      
       cout<<proc[i].Process_no<<"\t\t"<<
           stime[i]<<"\t\t"<<ctime[i]<<"\t\t"<<
           tat[i]<<"\t\t\t"<<wt[i]<<endl;
   }
  
// display the average waiting time and average turn around time
  
   cout<<"\nAverage waiting time : ";
   cout<<wavg/(float)tprocess<<endl;
   cout<<"\nAverage turnaround time : ";
   cout<<tavg/(float)tprocess<<endl;

}

int main()
{
int arrivaltime[] = { 1, 2, 3, 4 };
int bursttime[] = { 7, 1, 5, 3 };
int priority[] = { 3, 7, 4, 1 };
  
for(int i=0;i<tprocess;i++)
{
   proc[i].arrivaltime=arrivaltime[i];
   proc[i].bursttime=bursttime[i];
   proc[i].pr=priority[i];
   proc[i].Process_no=i+1;
   }
  
   //Using sort function
  
   sort(proc,proc+tprocess,comp);
  
   //Calling function findtime
  
   findtime();

   return 0;
}

Output:

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