C# Part 2 - Arrays - Exercise 3

using System;
using System.Collections.Generic;

class LexicographicalArrayCompare
{
    static byte GetArraySize(string arrayNum)
    {
        bool noError = false;
        byte arraySize = 0;
        do
        {
            Console.Write("Enter size of the {0} array: ", arrayNum);
            noError = byte.TryParse(Console.ReadLine(), out arraySize);
            if (!noError || arraySize == 0)
            {
                Console.WriteLine("incorrect size (probably symbol or 0 entered)!");
                Console.WriteLine("Try again <press Enter>...");
                Console.ReadLine();
                Console.Clear();
                noError = false;
            }
        } while (!noError);
        return arraySize;
    }

    static char[] GetArrayContent(string arrayNum, int size)
    {
        char[] arrayOutput = new char[size];
        string lettersInput = "";
        bool noError = false;
        int counter = 0;
        do
        {
            Console.Clear();
            Console.WriteLine("Enter {0} array elements on one line without spaces: ", arrayNum);
            lettersInput = Console.ReadLine().ToUpper();

            for (int i = 0; i < lettersInput.Length; i++)
            {
                if (counter == size)
                {
                    noError = true;
                    break;
                }
                if (lettersInput[i] < 'A' || lettersInput[i] > 'Z' || lettersInput[i] == ' ')
                {
                    Console.WriteLine("There was wrong input!");
                    Console.WriteLine("Try again <press Enter>...");
                    Console.ReadLine();
                    Console.Clear();
                    noError = false;
                    break;
                }
                else
                {
                    arrayOutput[counter] = Convert.ToChar(lettersInput[i]);
                    noError = true;
                    counter++;
                }

            }
        } while (!noError);
        return arrayOutput;
    }

    static Tuple<int, bool?> GetSmallerArray(int firstArray, int secondArray)
    {
        bool? longerArray = null; // null = equal; false = 2st array; true = 1st array
        if (firstArray > secondArray)
        {
            longerArray = true;
        }
        else if (firstArray < secondArray)
        {
            longerArray = false;
        }
        firstArray ^= secondArray;
        secondArray = firstArray ^ secondArray;
        firstArray ^= secondArray;
        Tuple<int, bool?> result = Tuple.Create(secondArray, longerArray);
        return result;
    }

    static void Main()
    {
        // Write a program that compares two char arrays lexicographically (letter by letter).
        Console.Title = "Compare two char arrays lexicographycaly";
        char[] arrayOne = new char[GetArraySize("first")];
        char[] arrayTwo = new char[GetArraySize("second")];
        arrayOne = GetArrayContent("first", arrayOne.Length);
        arrayTwo = GetArrayContent("second", arrayTwo.Length);
        //compare lexicographically both arrays
        Tuple<int, bool?> biggerArray = GetSmallerArray(arrayOne.Length, arrayTwo.Length);
        for (int i = 0; i < biggerArray.Item1; i++)
        {
            // compare letter by letter
            // if difference -> array with smaller letter wins
            if (arrayOne[i] < arrayTwo[i])
            {
                Console.WriteLine("First Array is lexicographicaly first.");
                break;
            }
            else if (arrayOne[i] > arrayTwo[i])
            {
                Console.WriteLine("Second Array is lexicographicaly first.");
                break;
            }
            // if we are that last index and no diferences, we check length of arrays:
            //  - if equal -> both wins - else the smaller wins
            if (i + 1 == biggerArray.Item1 && !biggerArray.Item2.HasValue)
            {
                Console.WriteLine("Both Arrays are lexicographicaly equal.");
                break;
            }
            else if (i + 1 == biggerArray.Item1 && biggerArray.Item2.Value)
            {
                Console.WriteLine("Second Array is first lexicographicaly.");
                break;
            }
            else if (i + 1 == biggerArray.Item1 && !biggerArray.Item2.Value)
            {
                Console.WriteLine("First Array is first lexicographicaly.");
                break;
            }
        }
    }
}