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

Solutions

Solution 1

Python Code
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class Solution:
    def numWaterBottles(self, numBottles: int, numExchange: int) -> int:
        ans = numBottles
        while numBottles >= numExchange:
            numBottles -= numExchange - 1
            ans += 1
        return ans

Java Code
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class Solution {
    public int numWaterBottles(int numBottles, int numExchange) {
        int ans = numBottles;
        for (; numBottles >= numExchange; ++ans) {
            numBottles -= (numExchange - 1);
        }
        return ans;
    }
}

C++ Code
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class Solution {
public:
    int numWaterBottles(int numBottles, int numExchange) {
        int ans = numBottles;
        for (; numBottles >= numExchange; ++ans) {
            numBottles -= (numExchange - 1);
        }
        return ans;
    }
};

Go Code
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func numWaterBottles(numBottles int, numExchange int) int {
	ans := numBottles
	for ; numBottles >= numExchange; ans++ {
		numBottles -= (numExchange - 1)
	}
	return ans
}

TypeScript Code
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function numWaterBottles(numBottles: number, numExchange: number): number {
    let ans = numBottles;
    for (; numBottles >= numExchange; ++ans) {
        numBottles -= numExchange - 1;
    }
    return ans;
}

JavaScript Code
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/**
 * @param {number} numBottles
 * @param {number} numExchange
 * @return {number}
 */
var numWaterBottles = function (numBottles, numExchange) {
    let ans = numBottles;
    for (; numBottles >= numExchange; ++ans) {
        numBottles -= numExchange - 1;
    }
    return ans;
};

PHP Code
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class Solution {
    /**
     * @param Integer $numBottles
     * @param Integer $numExchange
     * @return Integer
     */
    function numWaterBottles($numBottles, $numExchange) {
        $ans = $numBottles;
        while ($numBottles >= $numExchange) {
            $numBottles = $numBottles - $numExchange + 1;
            $ans++;
        }
        return $ans;
    }
}