Time Complexity of a loop if the loop variables is reduced / increased exponentially by a constant amount as follows:

// Here c is a constant greater than 1

for (int i = 2; i <=n; i = pow(i, c)) {

// some O(1) expressions

}

//Here fun is sqrt or cuberoot or any other constant root

for (int i = n; i > 0; i = fun(i)) {

// some O(1) expressions

}

What is the returned value of the following function?

int Fun(int n) {

int i, j, k = 0;

for (i = n/2; i <= n; i++)

for (j = 2; j <= n; j = j * 2)

k = k + n/2;

return k;

}