Question

Write a recursive function is_pow2(n) that returns True if the positive integer n is an integer power of 2, and False otherwise. For example: function call return value is_pow2(1) True is_pow2(2) True is_pow2(3) False is_pow2(4) True is_pow2(5) False is_pow2(6) False is_pow2(7) False is_pow2(8) True is_pow2(9) False is_pow2(255) False is_pow2(256) True Hint: Consider using repeated floor division.

Answer 1

Answer:

In Python:

def is_power(n):

   if n > 2:

       n = n/2

       return is_power(n)

   elif n == 2:

       return True

   else:

       return False

Explanation:

This defines the function

def is_power(n):

If n is greater than 0

   if n > 2:

Divide n by 2

       n = n/2

Call the function

       return is_power(n)

If n equals 2

   elif n == 2:

Return True

       return True

If n is less than 2

   else:

Then, return false

       return False