C++ Program for Priority Scheduling Algorithm


Levels of difficulty: / perform operation:

For Algorithm and example
Go to operating system –> Priority Scheduling

C++ Program for FCFS

#include<iostream>
using namespace std;
int main() {
	int bt[20],p[20],wt[20],tat[20],pr[20],i,j,n,total=0,pos,temp,avg_wt,avg_tat;
	cout<<"Enter Total Number of Process:";
	cin>>n;
	cout<<"nEnter Burst Time and Priorityn";
	for (i=0;i<n;i++) {
		cout<<"nP["<<i+1<<"]n";
		cout<<"Burst Time:";
		cin>>bt[i];
		cout<<"Priority:";
		cin>>pr[i];
		p[i]=i+1;
		//contains process number
	}
	//sorting burst time, priority and process number in ascending order using selection sort
	for (i=0;i<n;i++) {
		pos=i;
		for (j=i+1;j<n;j++) {
			if(pr[j]<pr[pos])
			                pos=j;
		}
		temp=pr[i];
		pr[i]=pr[pos];
		pr[pos]=temp;
		temp=bt[i];
		bt[i]=bt[pos];
		bt[pos]=temp;
		temp=p[i];
		p[i]=p[pos];
		p[pos]=temp;
	}
	wt[0]=0;
	//waiting time for first process is zero
	//calculate waiting time
	for (i=1;i<n;i++) {
		wt[i]=0;
		for (j=0;j<i;j++)
		            wt[i]+=bt[j];
		total+=wt[i];
	}
	avg_wt=total/n;
	//average waiting time
	total=0;
	cout<<"nProcesst    Burst Time    tWaiting TimetTurnaround Time";
	for (i=0;i<n;i++) {
		tat[i]=bt[i]+wt[i];
		//calculate turnaround time
		total+=tat[i];
		cout<<"nP["<<p[i]<<"]tt  "<<bt[i]<<"tt    "<<wt[i]<<"ttt"<<tat[i];
	}
	avg_tat=total/n;
	//average turnaround time
	cout<<"nnAverage Waiting Time="<<avg_wt;
	cout<<"nAverage Turnaround Time="<<avg_tat;
	return 0;
}





Quantitative Aptitude
Reasoning
Programming
Interview