T9.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace codejam
{
    class T9
    {
        public static void Main()
        {
            List<string> output = new List<string>();
            var data = File.ReadAllLines("data.txt");
            int caseno = 0;
            var map = getMap();
            for (int i = 1; i < data.Length; i++)
            {

                string res = convert(data[i], map);
                output.Add(String.Format("Case #{0}: {1}", ++caseno, res));

            }
            File.WriteAllLines("output", output);
        }
        public static string convert(string input, Dictionary<char, string> map)
        {
            StringBuilder output = new StringBuilder();
            char[] word = input.ToCharArray();
            string last = " ";
            foreach (var ch in word)
            {
                output.Append(((last[0] == map[ch][0]) ? ' ' + map[ch] : map[ch]));
                last = map[ch];
            }
            return output.ToString(); ;
        }
        public static Dictionary<char, string> getMap()
        {
            Dictionary<char, string> map = new Dictionary<char, string>();
            int skip = 0;
            for (char i = 'a'; i <= 'z'; i++)
            {
                int newVal = i - 91;
                if (newVal == 24 || newVal == 31) skip++;
                int key = (newVal - skip) / 3;
                int rep = (newVal - skip) % 3 + 1;

                map.Add(i, (i == 's' || i == 'z' ? repeat((key).ToString(), 4) : repeat(key.ToString(), rep)));
            }
            map.Add(' ', "0");
            return map;
        }
        public static string repeat(string s, int t)
        {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < t; i++)
            {
                sb.Append(s);
            }
            return sb.ToString();
        }
    }
}