x& (-X) lowbit (x)

Just learn the tree-like array, see here when the Meng. After the inquiry, found that the original operation of the program, the data used are the complement, and thus resolved the

int Lowbit (x)

{

Return x& (-X);

}

Such as:

X =1:1 &-1 (set digits to 8) 0000 0001 & 1111 1111 = 1

x = 6:6 &-6 0000 0110

&1111 1010 = 2

To sum up, it is actually:

Find the 2^p (where the number of binary representations of p:x, the position of the first 1 in the right and left digits), such as the binary representation of 6 is 110, the left number 0th is 0, the first is 1, then p=1, so lowbit (6) = 2^1 = 2.