public class Demo {  

08     static int total(int day) {  

09         if (day == 10) {  

10             return 1;  

11         } else {  

12             return (total(day + 1) + 1) * 2;  

13         }  

14     }  

15    

16     public static void main(String[] args) {  

17         System.out.println("第一天共有 " + total(1) + " 個桃子");  

18     }  

19 }