2.1.2 fork()

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

int main ()
{
    int p1 = fork();
    int p2 = fork();
    int p3 = fork();
    if (p1 == 0 && p2 > 0 && p3 > 0 )
    {

          printf("Parent A (pid = %d)" , getppid());
        printf(" creates process B (pid = %d)",getpid());
        printf("\n");
        wait(NULL);
    }
    else if (p1 > 0 && p2 == 0 && p3 > 0)
    {

        printf("Parent A (pid = %d)" , getppid());
        printf(" creates process C (pid = %d)",getpid());
        printf("\n");
        wait(NULL);
    }
    else if (p1 > 0 && p2 > 0 && p3 == 0)
    {

        printf("Parent A (pid = %d)" , getppid());
        printf(" creates process D (pid = %d)",getpid());
        printf("\n");
        wait(NULL);
    }
     else if (p1 == 0 && p2 == 0 && p3 > 0)
    {

        printf("Parent B (pid = %d)" , getppid());
        printf(" creates process E (pid = %d)",getpid());
        printf("\n");
        wait(NULL);
    }
      else if (p1 > 0 && p2 == 0 && p3 == 0)
    {

        printf("Parent C (pid = %d)" , getppid());
        printf(" creates process G (pid = %d)",getpid());
        printf("\n");
        wait(NULL);
    }
    else if (p1 == 0 && p2 > 0 && p3 == 0)
    {

        printf("Parent B (pid = %d)" , getppid());
        printf(" creates process F (pid = %d)",getpid());
        printf("\n");
        wait(NULL);
    }
    else if (p1 == 0 && p2 == 0 && p3 == 0)
    {
        printf("Parent E (pid = %d)" , getppid());
        printf(" creates process I (pid = %d)",getpid());
        printf("\n");
        wait(NULL);
    }

}