书里面关于分类的判断有些麻烦，通过某一位为0为1来对数组元素进行分类。假如第3位为1，那么也就是元素x & 8 等于或不等于0，所以没必要非的用第几位去判断。

def once(array):
	
	reOR = 0
	for x in array:
		reOR ^= x
		
	bit1 = firstBit1(reOR)
	first = 0
	second = 0
	for x in array:
		if x & bit1 != 0:
			first ^= x
		else:
			second ^= x
	return first, second

def firstBit1(x):
	n = 1
	while True:
		if x & n != 0:
			return n
		else:
			n <<= 1