1.2的幂
正确写法：
class Solution {
public:
bool isPowerOfTwo(int n) {
if(n <= )
return false;
return (n & (n-)) == ;
}
};错误写法1：
&符号的短路原则，如果&前面为false了就不会计算后面的了
class Solution {
public:
bool isPowerOfTwo(int n) {
if(n <= )
return false;
returclass Solution {
public:
bool isPowerOfFour(int num) {
if(num <= )
return false;
if((num & (num - )) == ){
if(num & 0x55555555)
return true;
else
return false;
}
else
return false;
}
};n ((n-) & n) == ;
}
};
错误写法2
==符号的优先级比&高
class Solution {
public:
bool isPowerOfTwo(int n) {
if(n <= )
return false;
return n & (n-) == ;
}
};2.4的幂
class Solution {
public:
bool isPowerOfFour(int num) {
if(num <= )
return false;
if((num & (num - )) == ){
if(num & 0x55555555)
return true;
else
return false;
}
else
return false;
}
};3.3的幂
https://blog.csdn.net/u014218090/article/details/80152446