CBSE NET July 2016 PAPER II

Q. What is the value returned by the function f given below when n=100 ?

int f (int n)

{

{

if (n==0) then return n;

else

return n + f(n-2);

}

else

return n + f(n-2);

}

(A) 2550

(B) 2556

(C) 5220

(D) 5520

Ans :- (A)

Explanation:-

It's a recursive function. Its gives output like this, 100+98+96+94+...0. This series of sum shows there is a constant difference of 2. AP gives quick result.

AP = n(nf + nl)/2.

Here n is number of element,nf is first element of series,nl is last element of series. So , sum = 50(0+100)/2 = 2550.