WSCIPHER.cs

using System;
using System.Collections.Generic;

namespace www.spoj.pl._899_WSCIPHER
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                string line = Console.In.ReadLine();
                string[] nums = line.Split(new char[] { ' ' });
                if (nums.Length == 3)
                {
                    int k1 = 0;
                    int.TryParse(nums[0], out k1);
                    int k2 = 0;
                    int.TryParse(nums[1], out k2);
                    int k3 = 0;
                    int.TryParse(nums[2], out k3);

                    if (k1 == 0 && k2 == 0 && k3 == 0)
                        break;

                    string ciphertext = Console.In.ReadLine();

                    CipherGroup Group1 = new CipherGroup(k1);
                    CipherGroup Group2 = new CipherGroup(k2);
                    CipherGroup Group3 = new CipherGroup(k3);
                    int len = ciphertext.Length;
                    for (int i = 0; i < len; i++)
                    {
                        char c = ciphertext[i];
                        if (c >= 'a' && c <= 'i')
                        {
                            Group1.Add(c, i);
                        }
                        else if (c >= 'j' && c <= 'r')
                        {
                            Group2.Add(c, i);
                        }
                        else
                        {
                            Group3.Add(c, i);
                        }
                    }

                    Group1.Rotate();
                    Group2.Rotate();
                    Group3.Rotate();

                    string[] letters = new string[len];
                    Group1.AddToArray(letters);
                    Group2.AddToArray(letters);
                    Group3.AddToArray(letters);

                    Console.WriteLine(string.Join("", letters));
                }
            }
        }
    }

    public class CipherGroup
    {
        public int k { get; set; }
        public List<char> Letters { get; set; }
        public List<int> Positions { get; set; }
        public CipherGroup(int k1)
        {
            k = k1;
            Letters = new List<char>();
            Positions = new List<int>();
        }
        public void Add(char c, int p)
        {
            Letters.Add(c);
            Positions.Add(p);
        }
        public void Rotate()
        {
            int len = Letters.Count;
            if (len == 0) return;
            for (int i = 0; i < k; i++)
            {
                Letters.Insert(0, Letters[len - 1]);
                Letters.RemoveAt(len);
            }
        }

        public void AddToArray(string[] letters)
        {
            int len = Letters.Count;
            for (int i = 0; i < len; i++)
            {
                letters[Positions[i]] = Letters[i].ToString();
            }
        }
    }
}