8.27 - hard - 108

600. Non-negative Integers without Consecutive Ones

这题的递推公式实在是太tricky了。。。。

class Solution(object):
    def findIntegers(self, num):
        """
        :type num: int
        :rtype: int
        """
        x, y = 1, 2
        res = 0
        num += 1
        while num:
            if num & 1 and num & 2:
                res = 0
            res += x * (num & 1)
            num >>= 1
            x, y = y, x + y
        return res