13. Strings and Text Processing 20. ExtractPalindromes

using System;
using System.Collections.Generic;

class ExtractPalindromes
{
    static char[] GetPunctuationSigns()
    {
        List<char> allPunctiation = new List<char>();

        for (int i = 0; i < 128; i++)
        {
            if (char.IsPunctuation((char)i))
            {
                allPunctiation.Add((char)i);
            }
        }
        allPunctiation.Add((char)32);
        return allPunctiation.ToArray();
    }

    static void Main()
    {
        string str = @"Nice blue sky. No LaiaL flying in the sky. aABBAa will tot come in Bulgaria.";
        List<string> palindromes = new List<string>();

        string[] strArr = str.Split(GetPunctuationSigns(), StringSplitOptions.RemoveEmptyEntries);

        for (int i = 0; i < strArr.Length; i++)
        {
            int wordLength = strArr[i].Length;
            //Get lengths
            int halfLength = wordLength / 2;
            int righSideStartIndex = wordLength - halfLength;
            //Get Left and Right Side of word
            string leftSide = strArr[i].Substring(0, halfLength);
            string rightSide = strArr[i].Substring(righSideStartIndex, halfLength);
            //Prepare Right side for COMPARISON by Reversing Right side to look the same if they are ;)
            char[] rightSideRevArr = rightSide.ToCharArray();
            Array.Reverse(rightSideRevArr);
            string rightSideRev = new string(rightSideRevArr); //Here I have the string again

            //Compare both sides
            if (leftSide == rightSideRev)
            {
                palindromes.Add(strArr[i]);
            }
        }

        foreach (var item in palindromes)
        {
            Console.WriteLine(item);
        }
    }
}