Program to toggle 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 0, then set it to 1 and if it is 1 then set it to 0.
Input: N = 5, K = 2 Output: 7 5 is represented as 101 in binary and has its second bit 0, so toggling it will result in 111 i.e. 7. Input: N = 5, K = 1 Output: 4 5 is represented as 101 in binary and has its first bit is 1, so toggling it will result in 100 i.e. 4.
- Since XOR of unset and set bit results in a set bit and XOR of a set and set bit results in an unset bit. Hence performing bitwise XOR of any bit with a set bit results in toggle of that bit, i.e.
Any bit <bitwise XOR> Set bit = Toggle which means, 0 ^ 1 = 1 1 ^ 1 = 0
- So in order to toggle a bit, performing a bitwise XOR 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:
Time Complexity: O(1)
Auxiliary Space: O(1)