1518. Water Bottles

Description

There are numBottles water bottles that are initially full of water. You can exchange numExchange empty water bottles from the market with one full water bottle.

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

Given the two integers numBottles and numExchange, 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.

 

Constraints:

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

Solution

water-bottles.py

class Solution:
    def numWaterBottles(self, numBottles: int, numExchange: int) -> int:
        res = numBottles

        while numBottles >= numExchange:
            remain = numBottles%numExchange
            numBottles //= numExchange
            res += numBottles
            numBottles += remain

        return res

water-bottles.cpp

class Solution {
public:
    int numWaterBottles(int numBottles, int numExchange) {
        int res = numBottles;

        while (numBottles >= numExchange){
            int remaining = numBottles % numExchange;
            numBottles /= numExchange;
            res += numBottles;
            numBottles += remaining;
        }

        return res;

    }
};