#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>



int fib(int x) { /* slow/recursive implementation of Fib */
 int i, rint = (rand()%30); double dummy;
for (i=0; i<rint*100; i++) {dummy=2.345*i*8.765/1.234;}
if (x==0) return(0); else if (x==1) return(1); else return(fib(x-1)+fib(x-2));
}

struct timeval stop, start;
/*gettimeofday(&start, NULL);
//do stuff
gettimeofday(&stop, NULL);
printf("took %lu\n", stop.tv_usec - start.tv_usec);*/

int main()
{
    int pidp = 0;
    int pidc1 = 0;
    int pidc2 = 0;

    pidp = getpid();

    gettimeofday(&start, NULL);
    if((pidc1 = fork()) == 0)
    {
        pidc1 = getpid();
        printf("from C1: own PID=%d, parent's PID=%d\n", pidc1, pidp);
        fib(20);
    }
    else
    {
    wait();
    if((pidc2 = fork()) == 0)
    {
        pidc2 = getpid();
        printf("from C2: own PID=%d, parent's PID=%d\n", pidc2, pidp);
        fib(20);
    }
    else
    {
    wait();
    gettimeofday(&stop, NULL);
    printf("from P0: own PID=%d, PID of C1=%d, PID of C2=%d, total elapsed time in milliseconds=%lu\n", pidp, pidc1, pidc2, stop.tv_usec - start.tv_usec);
}
}
}