sjf.cpp

#include<iostream>
 
using namespace std;
 
int main()
{
    int n,bt[20],at[20],wt[20],tat[20],ct[20],avwt=0,avtat=0,i,j,pos,temp,p[20];
    cout<<"Enter total number of processes(maximum 20):";
    cin>>n;
 	//enter the burst process time
    cout<<"\nEnter Process Burst Time\n";
    for(i=0;i<n;i++)
    {
        cout<<"P["<<i+1<<"]:";
        cin>>bt[i];
    }
    //enter the arrival time
 	cout<<"\nEnter Process Arrival Time\n";
    for(i=0;i<n;i++)
    {
        cout<<"P["<<i+1<<"]:";
        cin>>at[i];
        p[i]=i+1;           //contains process number
    }
 
    //sorting burst time in ascending order using selection sort
    for(i=0;i<n;i++)
    {
        pos=i;
        for(j=i+1;j<n;j++)
        {
            if(bt[j]<bt[pos])
                pos=j;
        }
 
        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 0
 
    //calculating waiting time
    for(i=1;i<n;i++)
    {
        wt[i]=0;
        for(j=0;j<i;j++)
            wt[i]+=bt[j];
    }
 
    cout<<"\nProcess\t\tBurst Time\tWaiting Time\tTurnaround Time";
 
    //calculating turnaround time
    for(i=0;i<n;i++)
    {
        tat[i]=bt[i]+wt[i];
        avwt+=wt[i];
        avtat+=tat[i];
        cout<<"\nP["<<i+1<<"]"<<"\t\t"<<bt[i]<<"\t\t"<<wt[i]<<"\t\t"<<tat[i];
    }
 
    avwt/=i;
    avtat/=i;
    cout<<"\n\nAverage Waiting Time:"<<avwt;
    cout<<"\nAverage Turnaround Time:"<<avtat;
 
    return 0;
}