1.描述
Given an integer (signed 32 bits), write a function to check whether it is a power of 4.
Example:
Given num = 16, return true. Given num = 5, return false.
Follow up: Could you solve it without loops/recursion?
2.分析
3.代碼
class Solution {
public:
bool isPowerOfFour(int num) {
if (num <= 0) return false;
if (num == 1) return true;
return num % 4 == 0 ? isPowerOfFour(num / 4) : false;
}
};
