07. Query Mess

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace QueryMess
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                // Process input
                string[] line = Console.ReadLine().Split("&?".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
                // Stop execution
                if (line[0] == "END") { break; }

                // Store all key=values queries
                Dictionary<string, List<string>> queries = new Dictionary<string, List<string>>();

                // Process keys=values
                for (int i = 0; i < line.Length; i++)
                {
                    // Check if contains any key=value
                    bool containsQuery = line[i].IndexOf('=') != -1;
                    if (!containsQuery) { continue; }

                    string[] query = line[i].Split('=');
                    string key = query[0].Trim();
                    string value = query[1].Trim();

                    // Replace encoded spaces
                    string pattern = @"(%20|\+)+";
                    key = Regex.Replace(key, pattern, " ").Trim();
                    value = Regex.Replace(value, pattern, " ").Trim();

                    // Add key to dictionary
                    if (queries.ContainsKey(key) == false)
                    {
                        queries.Add(key, new List<string>());
                    }
                    // Add value to key
                    queries[key].Add(value);
                }

                // Print
                foreach (var query in queries)
                {
                    Console.Write("{0}=[{1}]",
                        query.Key,
                        string.Join(", ", query.Value));
                }
                Console.WriteLine();
            }
        }
    }
}