Javakurs/Übungsaufgaben/Fibonacci/Musterlösung

public class FibonacciNumbers {
	public static void main(String args[]) {
		printfibonacci(-1, 8);
	}

	/* outputs fibonacci numbers from argument one to argument two */
	public static void printfibonacci(int start, int end) {
		for (int i = start; i < end; i++) {
			System.out.println("fibonacci(" + i + ") = " + fibonacci(i));
		}
	}

	/* calculates a fibonacci number of n */
	public static int fibonacci(int n) {
		if (0 == n) {
			return 0;
		}

		if (1 == n) {
			return 1;
		}

		if (n > 1) {
			return fibonacci(n - 1) + fibonacci(n - 2);
		} else {
			System.out.println("Error! Fibonacci undefined for negativ values");
			return -1;
		}
	}
}

Alternative Lösung

public class Fibonacci {
	public static void main(String[] args) {
		System.out.print(fibonacci(5));
	}

	public static int fibonacci(int n) {
		if (n < 0) {
			System.out.print("Du hast eine negative Zahl eingegeben:");
		} else {
			if (n > 1) {
				n = fibonacci(n - 1) + fibonacci(n - 2);
			}
		}
		return n;
	}
}