Check whether the two numbers differ at one bit position only

Given two non-negative integers a and b. The problem is to check whether the two numbers differ at one bit position only or not.
Examples: 
 

Input : a = 13, b = 9
Output : Yes
(13)10 = (1101)2
(9)10 = (1001)2
Both the numbers differ at one bit position only, i.e,
differ at the 3rd bit from the right.

Input : a = 15, b = 8
Output : No

Approach: Following are the steps:
 

1. Calculate num = a ^ b.
2. Check whether num is a power of 2 or not. Refer this post.

Output: 
 

Yes

Time Complexity: O(1).

Auxiliary Space: O(1).