原题链接：https://leetcode-cn.com/problems/water-bottles/

代码：

1 class Solution:
2     def numWaterBottles(self, numBottles: int, numExchange: int) -> int:
3         total = numBottles
4         while(numBottles >= numExchange) :
5             numBottles -= numExchange
6             total += 1
7             numBottles += 1
8         return total