public class Rekursion {
  public Rekursion() {
    System.out.println(fibonacci(10));
    System.out.println(fibonacciIterativ(10));
    System.out.println("Result " + mystery(5));
  }

  public int fibonacci(int n) {
    if (n == 0) {
      return 0;
    } else if (n == 1) {
      return 1;
    } else {
      return fibonacci(n-1) + fibonacci(n-2);
    }
  }

  public int fibonacciIterativ(int n) {
    if (n == 0) {
      return 0;
    } else if (n == 1) {
      return 1;
    }

    int next = 0;

    int a = 1;
    int b = 0;

    for (int index = 0; index < n; index++) {
      next = a + b;
      a = b;
      b = next;
    }

    return next;
  }

  public int mystery(int n) {
    System.out.println(n);
    if (n <= 1) {
      return 1;
    }

    return n + mystery(n-1);
  }

  private static String getString(int binaryNum) {
    return String.valueOf(binaryNum);
  }
}