OS Lab Class#1

#include<stdio.h>

int main()
{
    int n,bt[20],wt[20],tat[20],avwt=0,avtat=0,i,j,at[20];
    printf("Enter total number of processes(maximum 20):");
    scanf("%d",&n);

    printf("\nEnter Process Arival Time & Burst Time\n");
    for(i=0;i<n;i++)
    {
        printf("P[%d]:",i+1);
        scanf("%d%d",&at[i],&bt[i]);
    }

    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];
    }

    printf("\nProcess\t\tBurst Time\tWaiting Time\tTurnaround Time\tArivel Time");


    // arival time
    for(i=0;i<n;i++){
        temp = at[i];
        if(at[i]>at[i+1]){
            at[i] = at[i=1];
            at[i+1] = at[i]
        }
    }

    //calculating turnaround time
    for(i=0;i<n;i++)
    {

        tat[i]=bt[i]+wt[i];
        avwt+=wt[i];
        avtat+=tat[i];



        printf("\nP[%d]\t\t%d\t\t%d\t\t%d\t\t%d",i+1,bt[i],wt[i],tat[i],at[i]);
    }

    avwt/=i;
    avtat/=i;
    printf("\n\nAverage Waiting Time:%d",avwt);
    printf("\nAverage Turnaround Time:%d",avtat);
    printf("\n\n Thank You Mam \n");

    return 0;
}