题解 | #汽水瓶#

递归求解即可

// https://www.nowcoder.com/practice/fe298c55694f4ed39e256170ff2c205f
#include <iostream>
using namespace std;

int solve(int x) {
    if (x == 0 || x == 1) return 0;
    if (x == 2) return 1;
    return x / 3 + solve(x / 3 + x % 3); // 喝当前的，加上喝完后再换的
}

int main() {
    int n;
    cin >> n;
    while (n != 0) {
        cout << solve(n) << endl;
        cin >> n;
    }
}