fork() and wait() system calls (Fibonacci, quicksort and merging these two)

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h> int main() {    int a=0, b=1, n=a+b,i,ii;    pid_t pid;    printf("Enter the number of a Fibonacci Sequence:\n");    scanf("%d", &ii);    if (ii < 0)
      printf("Please enter a non-negative integer!\n");    else    {
      pid = fork();
      if (pid == 0)
      {
         printf("Child is producing the Fibonacci Sequence...\n");
         printf("%d %d",a,b);
         for (i=0;i<ii;i++)
         {
            n=a+b;
            printf("%d ", n);
            a=b;
            b=n;
         }
         printf("Child ends\n"); 
      }
      else 
      {
         printf("Parent is waiting for child to complete...\n");
         wait(NULL);
         printf("Parent ends\n");
      }    }    return 0; }