Info 2019.11.15

package main;

import java.util.Scanner;

public class Main {

    public static void main(String[] args) throws InterruptedException {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Länge: ");
        final int length = scanner.nextInt();
        System.out.print("Suche: ");
        final int search = scanner.nextInt();
        scanner.close();

        int a[] = new int[length];
        for (int i = 0; i < length; i++) {
            a[i] = i;
        }

        try {
            //iterativ(a, search);
            recrusiv(a, search);
            System.out.println("FOUND");
        } catch (NumberNotFoundException e) {
            System.out.println("Die gegebene Nummer konnte nicht gefunden werden.");
        }

    }

    public static void iterativ(int[] a, int search) throws NumberNotFoundException {
        boolean found = false;
        int start = 0;
        int end = a.length - 1;
        while(!found) {
            int mid = ((end - start) / 2) + start;
            if (a[mid] >= search) {
                end = mid;
            } else {
                start = mid;
            }
            found = a[start] == search || a[end] == search;
            if (end - start >= -1 && end - start <= 1) {
                throw new NumberNotFoundException();
            }
        }
    }

    public static boolean recrusiv(int a[], int search) throws NumberNotFoundException {
        return recrusiv(a, search, 0, a.length - 1);
    }

    public static boolean recrusiv(int a[], int search, int start, int end) throws NumberNotFoundException {
        if (end - start >= -1 && end - start <= 1) {
            throw new NumberNotFoundException();
        }
        final int mid = start + ((end - start) / 2);
        if (a[mid] >= search) {
            end = mid;
        } else {
            start = mid;
        }
        return (a[start] == search || a[end] == search) ? true : recrusiv(a, search, start, end);
    }
}