C++题解 | #汽水瓶 10行代码#

#include <iostream>
using namespace std;
int main(){
    int N;
    while(cin >> N){
        if(N == 0) return 0;
        int count = 0;
        while(N >= 3){
            count += N / 3;
            N = N / 3 + N % 3;
        }
        if(N == 2)
            count++;
        cout << count << endl;
    }
}