题目
Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once.
解题思路
先把所有数异或，结果为1的位置则是这两数的差异，选取最后一个位1的位置，将所有数按照这个位置的不同分成两组，将每组再次异或就是结果
代码
class Solution:
def singleNumber(self, nums: List[int]) -> List[int]:
bitmask = 0
for n in nums:
bitmask ^= n
diff = bitmask & (-bitmask)
x = 0
for n in nums:
if n & diff:
x ^= n
return [x, x ^ bitmask]
