codewars030: Fibonacci, Tribonacci and friends

6 kyu https://www.codewars.com/kata/556e0fccc392c527f20000c5/train/java

//https://www.codewars.com/kata/556e0fccc392c527f20000c5/train/java
package codewars;
public class Xbonacci{
  public double[] xbonacci(){
    double[] arr = new double[n];
    if(n == 0){
      return arr;
    }
    final int size = n < signature.length ? n : signature.length;
    for(int i = 0; i < size; i++){
      arr[i] = signature[i];
    }
    if(n <= signature.length){
      return arr;
    }
    for(int i = signature.length; i < n; i++){
      double sum = 0;
      for(int j = 1; j <= signature.length; j++){
        sum += arr[i - j];
      }
      arr[i] = sum;
    }
    return arr;
  }
}