题解 | 汽水瓶

#include <iostream>
using namespace std;
int main() {
    int a;//存储
    while(true){
        cin>>a;
        int c = 0;//喝到的
        if(a == 0){
            break;
        }
        while(a/3 != 0){
            c = c + a/3;
            a = a%3 + a/3;
        }
        if(a == 2){
            c = c + 1;
        }
        cout<< c<<"\n";
    }
}