Program to clear K-th bit of a number N

Given a number N, the task is to clear the K-th bit of this number N. If K-th bit is 1, then clear it to 0 and if it is 0 then leave it unchanged.
Examples: 
 

Input: N = 5, K = 1
Output: 4
5 is represented as 101 in binary
and has its first bit 1, so clearing
it will result in 100 i.e. 4.

Input: N = 5, K = 2
Output: 5
5 is represented as 101 in binary
and has its second bit is already 0,
so clearing it will result in 101 i.e. 5.

Approach: 
 

• Since bitwise AND of any bit with a reset bit results in a reset bit, i.e.

Any bit <bitwise AND> Reset bit = Reset bit

which means,
0 & 0 = 0
1 & 0 = 0

• So for clearing a bit, performing a bitwise AND of the number with a reset bit is the best idea.

n = n & ~(1 << k)
OR
n &= ~(1 << k)

where k is the bit that is to be cleared

Below is the implementation of the above approach:
 

4

Time Complexity: O(1)

Auxiliary Space: O(1)