面试题 16.21. 交换和

给定两个整数数组，请交换一对数值（每个数组中取一个数值），使得两个数组所有元素的和相等。

返回一个数组，第一个元素是第一个数组中要交换的元素，第二个元素是第二个数组中要交换的元素。若有多个答案，返回任意一个均可。若无满足条件的数值，返回空数组。

示例:

输入: array1 = [4, 1, 2, 1, 1, 2], array2 = [3, 6, 3, 3]
输出: [1, 3]

示例:

输入: array1 = [1, 2, 3], array2 = [4, 5, 6]
输出: []

提示：

• 1 <= array1.length, array2.length <= 100000

Python 解答：

class Solution:
    def findSwapValues(self, array1: List[int], array2: List[int]) -> List[int]:
        sum1 = sum(array1)
        sum2 = sum(array2)
        diff = sum1-sum2
        if diff % 2 != 0:
            return []
        else:
            diff //= 2
        for i in set(array1):
            for j in set(array2):
                if i - j == diff:
                    return [i, j]
        return []