Given an integer, write a function to determine if it is a power of two.
Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.
代码如下：
public class Solution {
public boolean isPowerOfTwo(int n) {
if(n<=0) return false;
if(n==1) return true;
int mod=n;
while(mod>=2 && mod%2==0){
mod/=2;
}
if(mod>=2 && mod%2!=0)
return false;
else
return true;
}
}
运行结果：