数组中只出现一次的数字

微信图片_20191223132546.jpg

class Solution:
    # 返回[a,b] 其中ab是出现一次的两个数字
    def FindNumsAppearOnce(self, array):
        # write code here
        if len(array)<2:
            return None
         
        res = None
        for num in array:
            if res == None:
                res = num
            else:
                res = res ^ num
        count = 0
        while res % 2 == 0:
            res = res >> 1
            count += 1
        mask = 1 << count
        
        first = None
        second = None
        for num in array:
            if mask & num == 0:
                if first == None:
                    first = num
                else:
                    first = first ^ num
            else:
                if second == None:
                    second = num
                else:
                    second = second ^ num
        return first, second