5464. Water Bottles

Given numBottles full water bottles, you can exchange numExchange empty water bottles for one full water bottle.

The operation of drinking a full water bottle turns it into an empty bottle.

Return the maximum number of water bottles you can drink.

Example 1:

Input: numBottles = 9, numExchange = 3
Output: 13
Explanation: You can exchange 3 empty bottles to get 1 full water bottle.
Number of water bottles you can drink: 9 + 3 + 1 = 13.

Example 2:

Input: numBottles = 15, numExchange = 4
Output: 19
Explanation: You can exchange 4 empty bottles to get 1 full water bottle. 
Number of water bottles you can drink: 15 + 3 + 1 = 19.

Example 3:

Input: numBottles = 5, numExchange = 5
Output: 6

Example 4:

Input: numBottles = 2, numExchange = 3
Output: 2

Constraints:

• 1 <= numBottles <= 100
• 2 <= numExchange <= 100

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很贴近生活的一个题。初始有n瓶满饮料，喝完之后，可以每m个空瓶子换一瓶新饮料，问最终能喝多少瓶饮料。

直接模拟，代码如下：

class Solution {
public:
	int numWaterBottles(int numBottles, int numExchange) {
		int full = numBottles, empty = 0, div = numExchange;
		int ans = 0;
		while (full + empty >= div) {
			ans += full;
			empty += full;
			full = empty / div;
			empty = empty % div;
		}
		return ans + full;
	}
};

本代码提交AC。