Telerik Letter-based sort with "less than" filter.

//////////////////////////////////////////////////////////////////////////////
// Possible sort algorithm of Telerik's letter-based "Less Than" grid filter.
//
// Note:  to run this example use a C# Console app or download LINQPad
//        from http://www.linqpad.net/
//////////////////////////////////////////////////////////////////////////////

// List<string> input = new List<string> {  "someprovider01", "someprovider02", "someprovider00", "404", "1000" };
List<string> input = new List<string> {  "100", "200", "300", "400", "500", "600", "1000" };

// Letter based sort first.
var sortedList = from i in input
         orderby i ascending
         select i;

sortedList.Dump(); // OUTPUT    "100", "1000", "200", "300", "400", "500", "1000"

// Create an index on the sorted list.
var indexedList = (from i in sortedList.Select((number, index) => new { index, number })
           select i).ToDictionary(item => item.index, item => item.number);

indexedList.Dump(); // OUTPUT   0 : "100", 1 : "1000", 2 : "200", 3 : "300", 4 : "400", 5 : "500", 6 : "1000

// Get last postion in regards to "less than" 500
int lastOrdinal = (from i in indexedList
           where Convert.ToInt32(i.Value) == 500
           select i.Key).Single();

lastOrdinal.Dump(); // OUTPUT   5


var lessThan500 = from i in indexedList
          where i.Key < lastOrdinal
          select i.Value;

lessThan500.Dump(); // OUTPUT:  100, 1000, 200, 300, 400