How to get position of right most set bit in C

Question

int a = 12;

for eg: binary of 12 is 1100 so answer should be 3 as 3rd bit from right is set.

I want the position of the last most set bit o

Answer 1

Check if a & 1 is 0. If so, shift right by one until it's not zero. The number of times you shift is how many bits from the right is the rightmost bit that is set.