题解 | #汽水瓶#

模拟：剩余两瓶就➕一瓶

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        for (int n = in.nextInt(); n != 0; n = in.nextInt()) {
            int ans = 0;
            for (;n > 1; n = n / 3 + n % 3 + (n / 3 + n % 3 == 2 ? 1 : 0)) {
                ans += n / 3;
            }
            System.out.println(ans);
        }
    }
}