UVa 11877 – The Coco-Cola Store
Once upon a time, there was a special Coca-Cola store. If you return three empty bottles to the store, you will receive one full bottle of Coca-Cola to drink. If you have N empty bottles, how many bottles of Coca-Cola can you drink at most?
Hint: Let me tell you how to drink 5 bottles of Coca-Cola with 10 empty bottles: Use 9 empty bottles to exchange for 3 full bottles, drink them to get 3 empty bottles, then use these empty bottles to exchange for one full bottle. Now you have 2 empty bottles. Borrow one empty bottle from the store, then exchange for one full bottle. Drink it, and finally return the last empty bottle to the store.
Sample Inputs/Outputs
| Sample Input(s) | Sample Output(s) |
|---|---|
| EOF input. Each test case consists of one line containing an integer N (1 ≤ N ≤ 100). The input ends with N = 0, which should not be processed. | For each test case, output the number of full bottles of Coca-Cola you can drink. |
| 3 10 81 0 | 1 5 40 |
Thought Process
Use a while loop (N >= 3). Inside the loop, declare a variable 'bottle' representing the number of Coca-Cola bottles you can drink, which is N/3. Then, update the answer += bottle, N -= bottle*3, and N += bottle.
Since you can borrow empty bottles from the store, add a conditional statement outside the while loop. If N == 2 after the while loop ends, it means you can borrow a bottle, so increment the answer by 1.
Sample Code－ZeroJudge N803: The Coco-Cola Store
#include <iostream>
using namespace std;
int main() {
cin.sync_with_stdio(0);
cin.tie(0);
int N;
while (cin >> N && N != 0) {
int ans = 0;
while (N >= 3) {
int bottle = N/3;
ans += bottle;
N -= bottle*3;
N += bottle;
}
if (N == 2) ans++;
cout << ans << "\n";
}
}
//ZeroJudge N803
//Dr. SeanXD