12_Water_bottles.cpp

// 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.






// Optimal solution for this problem 

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

        while (empty >= numExchange) {
            empty -= numExchange; 
            empty += 1;        
            count++;
        }

        return count;
    }
};