编写java程序求裴波那契数列前20项和

public class Fiboncci {
public static void main(String[] agrs) {
      int i;
      double sum=0;
      int f[]=new int[20];
      f[0]=1;f[1]=1;
      for (i = 0; i < 20; i++) // 开始循环体
  {
   if (i == 0 || i == 1)
                       {
    sum = sum + f[i];
          }
                        else
                        {
    f[i] = f[i - 1] + f[i - 2];
    sum = sum + f[i];
    }
                 }

      System.out.println("Fiboncci数列前"+ i +"项的和为:"+sum);
   }
}