Change all even bits in a number to 0

Given a number, change all bits at even positions to 0.

Examples: 

Input : 30
Output : 10
Binary representation of 11110. 
Bits at Even positions are highlighted. 
After making all of them 0, we get 01010

Input : 10
Output : 10

Method 1 (Bit Traversal)

The idea is to traverse through all even bits. We accumulate all powers of 2 in a number to subtract. Finally we subtract the accumulated value from n to obtain the result. 

10

Time Complexity - O(log n)

Space Complexity - O(1)

Method 2: (Bit masking)

10

Time Complexity - O(1)

Space Complexity - O(1)