Given an integer, write a program to clear the right most set bit in it’s binary representation.

For example, consider a number 54. It is represented in binary as

1 1 0 10.1

The right most set bit is marked in bold. We need to convert this to

1 1 0 100

Let us look at the approach step by step.

If you negate the number to -54, it is represented in computer’s memory in 2’s compliment.

0 0 1 0 1 0

Let us perform a bit-wise AND operation between these two.

1 1 0 1 1 0

0 0 1 0 1 0

————&

0 0 0 0 1 0

Subtract this from the original number to get the result. So x – ( x & -x) gives the required answer.

Here is the simple program to test the above.