两种方法算出后一位等于前两位数字的和

  protected void Page_Load(object sender, EventArgs e)
    {
        //两种方法算出后一位等于前两位数字的和
        if (!IsPostBack)
        {
            int[] num = new int[30];
            num[0] = 1;
            num[1] = 1;
            int first = num[0];
            int second = num[1];
            for (int i = 2; i < num.Length; i++)
            {
                num[i] = first + second;
                first = second;
                second = num[i];
            }
            Response.Write(num[29]);
            Response.Write("<br/>");
            Response.Write(Foo(30).ToString());
        }

    }

 

    public static int Foo(int i)
    {
        if (i < 3)
            return 1;
        else return Foo(i - 1) + Foo(i - 2);
    }