using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            char[] alfabet = new char[] { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y','z' };

            label1.Text = ""+alfabet[1];

            string k = textBox1.Text;
            string kluczdlugosci = k;
            string m = textBox2.Text;

            label4.Text = "dlugosc m = " + m.Length;

            int j = 0;
            int dlugosc =  m.Length - k.Length;

            for (int i = 0; i < dlugosc; i++)
            {
                if (i % k.Length == 0) {
                    j = 0;
                }
                kluczdlugosci += k.Substring(j, 1);
                j++;
            }

            label5.Text = "klucz dlugosci " + kluczdlugosci;

            string indeksy = "";
            string szyfr = "";
            for (int i = 0; i < m.Length; i++)
            {
                char[] myChar = m.Substring(i, 1).ToCharArray();
                char[] myChar1 = kluczdlugosci.Substring(i, 1).ToCharArray();
                int indeksM = Array.IndexOf(alfabet, myChar[0]);
                int indeksK = Array.IndexOf(alfabet, myChar1[0]);
                int c = (indeksM + indeksK) % 26;
                indeksy += "" + indeksM + " " + indeksK + " \n";

                szyfr += "" + alfabet[c+1];
            }

            label6.Text = "" + indeksy;
            label7.Text = "" + szyfr;

            /**/

            string indeksy1 = "";
            string szyfr1 = "";
            for (int i = 0; i < m.Length; i++)
            {
                char[] myChar = szyfr.Substring(i, 1).ToCharArray();
                char[] myChar1 = kluczdlugosci.Substring(i, 1).ToCharArray();
                int indeksM = Array.IndexOf(alfabet, myChar[0]);
                int indeksK = Array.IndexOf(alfabet, myChar1[0]);
                int c = (indeksM + indeksK) % 26;
                indeksy += "" + indeksM + " " + indeksK + " \n";

                szyfr += " " + alfabet[c + 1];
            }

            label6.Text = "" + indeksy;
            label7.Text = "" + szyfr;
        }
    }
}