交换数字(不用临时变量)

编写一个函数，不用临时变量，直接交换numbers = [a, b]中a与b的值。

示例：

输入: numbers = [1,2]
输出: [2,1]

示例代码：

class Solution(object):
    def swapNumbers(self, numbers):
        """
        :type numbers: List[int]
        :rtype: List[int]
        """
        return [numbers[1], numbers[0]]

思路解析：返回list

示例代码2：

class Solution(object):
    def swapNumbers(self, numbers):
        """
        :type numbers: List[int]
        :rtype: List[int]
        """
        numbers[0] ^= numbers[1]
        numbers[1] ^= numbers[0]
        numbers[0] ^= numbers[1]
        return numbers

思路解析：异或交替求解（可以防止溢出），与加减法类似

示例代码3：

class Solution(object):
    def swapNumbers(self, numbers):
        """
        :type numbers: List[int]
        :rtype: List[int]
        """
        numbers[0] = numbers[0] + numbers[1]
        numbers[1] = numbers[0] - numbers[1]
        numbers[0] -= numbers[1]
        return numbers

思路解析：加减法

示例代码4：

class Solution(object):
    def swapNumbers(self, numbers):
        """
        :type numbers: List[int]
        :rtype: List[int]
        """
        return numbers[::-1]

思路解析：切片