Position of rightmost set bit

Given an integer n, Return the position of the first set bit from right to left in the binary representation n. If no set bits present , then return 0.
Note: Position of rightmost bit is 1.

Examples:

Input: n = 18
Output: 2
Explanation: Binary representation of 18 is 10010, hence position of first set bit from right is 2.

Input:  n = 19
Output: 1
Explanation: Binary representation of 19 is 10011, hence position of first set bit from right is 1.

Using 2's complement and log Operator - O(log n) time and O(1) space

The idea is to find the rightmost set bit using a property of 2's complement arithmetic. When we perform n & (~n + 1) or equivalently n & (-n), we get a number with only the rightmost set bit of n. Then we can use log2 to find its position.

2

Using left shift operator - O(1) time and O(1) space

The idea is to use a counter and iteratively left-shift 1 to check each bit position. Increment a position counter until we find a bit that is set.

2

Using right shift operator - O(1) time and O(1) space

The idea is to right-shift the number and check the least significant bit in each iteration. Increment a position counter until we find a bit that is set.

2

Using Built-In Library Functions - O(1) time and O(1) space

2