其中一种是这样，就是过不了，好气啊 import java.util.Scanner; public class Main {     public static void main(String[] args) {         Scanner sc=new Scanner(System.in);         int n;         while(sc.hasNext()){         n=sc.nextInt();             System.out.println(sum(n));         }         sc.close();     }     public static int sum(int i){         if(i<=4){             return i;         }else{             return sum(i-1)+sum(i-3);         }     } }