CareerCup

My answer:

First sub question answer :

i = 0 ;
while (i < n )
{
fork();
printf("\n SIVA");
i++;
}

1) if n > 0, 2^n + 2^n-1 + .... 2^1

Second sub question answer :

i = 0 ;
while (i < n )
{
printf("\n SIVA");
fork();
i++;
}

2) if n > 0, 2^n-1 + 2^n-2 + ... + 2^0

I guess you could write like a recurrence solution (T(n) would be the answer for n iterations) and then solve it.

Like in the first case, it will be T(n)=2+2T(n-1) and T(1) = 2.

in the second case, it would be T(n)=1+2T(n-1) and T(1) = 1.

Solve for T(n).

Few interview questions on fork()
How many processes are created in this snippet?
Main()
{
Fork();
Fork() && fork () || fork ();
Fork ();
}
anandtechblog.blogspot.com/2011/07/process-flow.html