First Come First Serve

#include <stdio.h>
#include <conio.h>
void main(){
    char pid[12], at[12]={0, 0, 2, 2, 2, 10, 10, 15, 20, 30, 40, 40}, et[12]={10,3,2,1,4,5,7,8,10,9,3,2}, ct[12], wt[12], tt[12];
    int i, time, N=12, sumWT=0, sumTT=0;
    float avgWT, avgTT;
    clrscr();
    for(i = 0; i < N; i++) pid[i] = i+ 65;
    time = 0;
    for(i = 0;;){
        if(time >= at[i]){
            ct[i] = time + et[i];
            time = ct[i];
            wt[i] = ct[i] - (at[i] + et[i]);
            tt[i] = ct[i] - at[i];
            i++;
        }
        else time++;
        if(i == N) break;
    }
    printf("pid\tAT\tET\tCT\t\WT\tTT\n");
    for(i = 0; i < N; i++){
        printf("%c\t%d\t%d\t%d\t%d\t%d\n", pid[i], at[i], et[i], ct[i], wt[i], tt[i]);
        sumWT+=wt[i];
        sumTT+=tt[i];
    }
    avgWT = sumWT/12.0;
    avgTT = sumTT/12.0;
    printf("\nThe average waiting time is %.2f \n", avgWT);
    printf("The average turn-around time is %.2f\n", avgTT);
    getch();
}