解題絲路  fn = f(n)  , gn=g(n) 至於 f(n) = n + f(n-1) 

f(n-1)就會是 上一個迴圈的fn

n 是 i

import java.util.Scanner;

public class a216 {
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);
        while (input.hasNextInt()) {
            int n = input.nextInt();
            long fn = 0;
            long gn = 0;
            for (int i = 1; i <= n; i++) {
                    fn = i + fn;
                    gn = fn + gn; //gn 跟現在的fn會跟上一個gn 
            }
            System.out.print(fn + " ");
            System.out.println(gn);
        }

    }
}