leetcode 1237

class Solution:
    def findSolution(self, customfunction: 'CustomFunction', z: int) -> List[List[int]]:
        x,y = 1,1001
        res = []
        while x < 1001 and y > 0:
            v = customfunction.f(x,y)
            if v < z:
                x += 1
            elif v > z:
                y -= 1
            else:
                res.append([x,y])
                x += 1
                y -= 1
        return res

我没太理解这题是要干什么，参考https://leetcode.com/problems/find-positive-integer-solution-for-a-given-equation/discuss/414158/JavaPython-3-3-methods%3A-time-O(x-%2B-y)-O(xlogy)-and-O(x-%2B-logy)-w-analysis.