Helper.java

package banknoten;

import java.util.Random;
import java.util.Scanner;

public class Helper {
    public static String ReadLine() {
        return ReadLine(new Scanner(System.in), 0);
    }
    public static String ReadLine(Scanner sc, int musthaveLength) {

        if (sc.hasNext()) sc.nextLine();
        String res = "";
        if(musthaveLength != 0) {
            while(res.trim().length() != musthaveLength) {
                res = sc.nextLine();
                System.out.println(res.trim().length());
            }
        } else {
            res = sc.nextLine();
        }
        return res;
    }

    public static String RandString(int length) {
        String characters = "abcdefghijklmnopqrstuvwxyz";
        characters += characters.toUpperCase();
        char[] _chars = characters.toCharArray();

        StringBuilder sb = new StringBuilder();
        for (int i : new int[length]) {
            sb.append(Character.toString(_chars[new Random(((length-1 < 0 || length-1 > _chars.length) ? 0 : length)).nextInt()]));
        }
        return sb.toString();
    }
    public static int getLatinIndex(char input) {
        char[] _latinchars = "abcdefghijklmnopqrstuvwxyz".toUpperCase().toCharArray();
        char _char = Character.toString(input).toUpperCase().charAt(0);
        int counter = 0;
        for(char c : _latinchars) {
            if(_char == c) return counter;
            counter++;
        }
        return -1;
    }
}