给定3个列表，找出前两个列表中的哪两个元素的和尽可能接近第三个列表中的每个值

def find_closest_sum(list1, list2, list3):
    diff = float('inf')
    res = []

    for target in list3:
        left = 0
        right = len(list1) - 1

        while left < len(list1) and right >= 0:
            temp_sum = list1[left] + list2[right]
            temp_diff = abs(temp_sum - target)

            if temp_diff < diff:
                diff = temp_diff
                res = [list1[left], list2[right]]

            if temp_sum == target:
                return res
            elif temp_sum > target:
                right -= 1
            else:
                left += 1

    return res