Query Mess

/* The input is passed as array of query strings. For each field of the form, the query string contains a pair field=value. Within each pair, the field name and value are separated by an equals sign, '='. The series of pairs are separated by the ampersand, '&’. The question mark is used as a separator and is not part of the query string. SPACE is encoded as '+' or "%20". URL query string may contain another URL as value. Print at single line each processed string as follows:  key=[value]nextkey=[another  value] … etc. Multiple whitespace characters should be reduced to one inside value/key names, but there shouldn’t be any whitespaces before/after extracted keys and values. If a key already exists, the value is added with comma and whitespace after other values of the existing key in current string. */

namespace _07.QueryMess
{
    using System;
    using System.Collections.Generic;
    using System.Text;
    using System.Text.RegularExpressions;

    class QueryMess
    {
        static void Main(string[] args)
        {
            Queue<string> linkStrings = new Queue<string>();
            StringBuilder inputLine = new StringBuilder(Console.ReadLine());
            while (inputLine.ToString() != "END")
            {
                linkStrings.Enqueue(inputLine.ToString());
                inputLine.Clear();
                inputLine.Append(Console.ReadLine());
            }

            foreach (string link in linkStrings)
            {
                GetPairsFromLinkString(link);
            }

        }

        private static void GetPairsFromLinkString(string link)
        {
            Dictionary<string, Queue<string>> pairs = new Dictionary<string, Queue<string>>();
            const string pattern = @"[^=&?\s]+=[^=&?\s]+";
            MatchCollection matches = Regex.Matches(link, pattern);
            foreach (Match match in matches)
            {
                Regex rgx = new Regex(@"(\+|%20)+");
                string pair = rgx.Replace(match.ToString(), " ");
                string[] fieldNames = pair.Split('=');
                string key = fieldNames[0].Trim();
                string value = fieldNames[1].Trim();

                if (!pairs.ContainsKey(key))
                {
                    pairs[key] = new Queue<string>();
                }

                pairs[key].Enqueue(value);
            }

            PrintResultString(pairs);
        }

        private static void PrintResultString(Dictionary<string, Queue<string>> pairs)
        {
            StringBuilder result = new StringBuilder();
            foreach (var entry in pairs)
            {
                result.Append(entry.Key).Append("=[");
                result.Append(string.Join(", ", entry.Value)).Append("]");
            }

            Console.WriteLine(result);
        }
    }
}