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);
}