C Program to Implement SJF CPU Scheduling Algorithm

#include<stdio.h>
#include<conio.h>
#include<string.h>
void main()
{
    int et[20],at[10],n,i,j,temp,st[10],ft[10],wt[10],ta[10];
    int totwt=0,totta=0;
    float awt,ata;
    char pn[10][10],t[10];
    //clrscr();
    printf("Enter the number of process:");
    scanf("%d",&n);
    for(i=0; i<n; i++)
    {
        printf("Enter process name, arrival time& execution time:");
        //flushall();
        scanf("%s%d%d",pn[i],&at[i],&et[i]);
    }
    for(i=0; i<n; i++)
        for(j=0; j<n; j++)
        {
            if(et[i]<et[j])
            {
                temp=at[i];
                at[i]=at[j];
                at[j]=temp;
                temp=et[i];
                et[i]=et[j];
                et[j]=temp;
                strcpy(t,pn[i]);
                strcpy(pn[i],pn[j]);
                strcpy(pn[j],t);
            }
        }
    for(i=0; i<n; i++)
    {
        if(i==0)
            st[i]=at[i];
        else
            st[i]=ft[i-1];
        wt[i]=st[i]-at[i];
        ft[i]=st[i]+et[i];
        ta[i]=ft[i]-at[i];
        totwt+=wt[i];
        totta+=ta[i];
    }
    awt=(float)totwt/n;
    ata=(float)totta/n;
    printf("\nPname\tarrivaltime\texecutiontime\twaitingtime\ttatime");
    for(i=0; i<n; i++)
        printf("\n%s\t%5d\t\t%5d\t\t%5d\t\t%5d",pn[i],at[i],et[i],wt[i],ta[i]);
    printf("\nAverage waiting time is:%f",awt);
    printf("\nAverage turnaroundtime is:%f",ata);
    getch();
}

 OUTPUT:

Enter the number of process:3
Enter process name, arrival time& execution time:2 5 7
Enter process name, arrival time& execution time:3 6 14
Enter process name, arrival time& execution time:4 7 12

Pname   arrivaltime     executiontime   waitingtime     tatime
2           5               7               0               7
4           7              12               5              17
3           6              14              18              32
Average waiting time is:7.666667
Average turnaroundtime is:18.666666