Problem 1: Without Wait?

Below it is a typical problem to print something in child.

/* Wait/problematic.c */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>


int main(int argc,char *argv[])
{
    printf("Before fork...\n");
    if(fork() == 0)
    {
        printf("Hello World!\n");
        exit(0);
    }
    printf("After fork..\n");
    return 0;
}

We expect the output to be:

Before fork...
Hello World!
After fork...

However, the actual output may become

Before fork...
After fork...
Hello World!

We would like to suspend the parent and let the child finish execution.