leetcode 342 Power of 4

class Solution {
public:
    bool isPowerOfFour(int num) {
        /*
        16 10000    4的倍数的二进制数字中0的个数为偶数个
        zeroCount : 统计转换成二进制数据中0的个数
        tmp : 用来保存二进制结果
        */
        if (num <= 0) return false;
        if (num == 1) return true;
        vector<int> tmp;
        int zeroCount = 0;
        while (num > 0) {
            tmp.push_back(num % 2);
            num = num / 2;
        }
        for (auto item : tmp) {
            cout << item << endl;
        }
        // 判断数组的长度也是个问题 
        if (tmp[tmp.size() - 1] == 1) {
            int i = tmp.size() - 2;
            for (i >= 0; i >= 0; i--) {
                if (tmp[i] == 0) {
                    zeroCount = zeroCount + 1;
                }
                // 刚开始忘了这一句,只去考虑了计算0个个数,如果一旦前size-1数字中出现1,那么肯定不是幂
                else
                    return false;
            }
            if (zeroCount > 0 && zeroCount % 2 == 0)
                return true;
            else
                return false;
        }
        else
            return false;
        return false;
    }
};

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