参考代码：

import sys


class Solution:
    def twoSum(self, n, target):
        n.sort()
        i, j = 0, len(n)
        diff = sys.maxsize
        while i < j:
            if n[i] + n[j] < target:
                diff = min(diff, target - n[i] - n[j])
                i += 1
            else:
                diff = min(diff, n[i] + n[j] - target)
                j -= 1
        return diff