来自位模式的真值（1）的第一个位置

Question

For example, if the pattern is as follows:

bit        [10010][1011][1000]
position    54321  4321  4321  
result         2      1  4

I want to get the result from right to left position as [2] [1] [4]

Answer 1

If I understand your question correctly, you are looking for a function that returns the index of the least significant 1-bit in an integer. If so, check whether your platform implements the function ffs() ["find first set"]. On Linux, you can do "man ffs" to get the full documentation. On other programming platforms the function may be named differently, e.g. in NVIDIA's CUDA, it exists as a device function __ffs().