Power of Two(算法)
4:
2
2
2^2
22 true 9:
3
2
3^2
32 false 16:
4
2
4^2
42 =
2
4
2^4
24 true
1.mod; 2.log2 => int; 3.位运算; x & (x - 1) 判断: x != 0 && x & (x - 1) == 0
python
def isPowerOfTwo(self
, n
):
return n
> 0 and not (n
& n
- 1)
java
bool
isPowerOfTwo(int n
) {
return n
> 0 && !(n
& (n
- 1));
}
