What is the output of this function?

Run the following Java code for your answer:

public class OutputOfFunction {

public static void main(String[] args) {

for (int i=0; i<25; i++) {

System.out.println("fun("+i+") = "+fun(i));

}

}

static int fun(int n) {

if (n==0)

return 2;

else

return 4 + fun(n/2);

}// end fun

} // end class

For the code above (except it should be Fun(n/2)) ... for n=0 to 24 ... results below ... looks like at the change of any "2 to the power of" we increase by 4 after starting with 2 at the start ... so at 2 to the power of 0 (=1) we get 2+4=6, at 2 to the power of 1 (=2) we get 6+4=10, at 2 to the power of 2 (=4) we get 10+4=14, at 2 to the power of 3 (=8) we get 14+4=18 etcetera ... values between show no change:

[Session started at 2012-12-13 20:29:11 +1100.]

Fun(0) is 2

Fun(1) is 6

Fun(2) is 10

Fun(3) is 10

Fun(4) is 14

Fun(5) is 14

Fun(6) is 14

Fun(7) is 14

Fun(8) is 18

Fun(9) is 18

Fun(10) is 18

Fun(11) is 18

Fun(12) is 18

Fun(13) is 18

Fun(14) is 18

Fun(15) is 18

Fun(16) is 22

Fun(17) is 22

Fun(18) is 22

Fun(19) is 22

Fun(20) is 22

Fun(21) is 22

Fun(22) is 22

Fun(23) is 22

Fun(24) is 22

answer will be 2 if n= o else 4+ fun(n/2). This is called recursion . Let say n = 8

then answer will be: 8/2= 4/2= 2/2= 1/2 =0 = 4 +4 +4+4+4 =20.

i.e. 4 + (number of times you can divide number by 2)* 4

so for n = 13

13/2 =6/2 =3/2= 1/2= 0 = 4*4 + 4= 20

fun(4);

/

fun(3), print(3), fun(2)(prints 0 1)

/

fun(2), print(2), fun(1)(prints 0)

/

fun(1), print(1), fun(0)(does nothing)

/

fun(0), print(0), fun(-1) (does nothing)