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​

using System;

using System.Collections.Generic;

using System.Linq;

​

public class SearchResultRow {

    public int Intid {get;set;}

    public int UpdateCount {get;set;}

    public DateTime? Tlc {get;set;}

    public SearchResultRow(int id, int? updCount, DateTime? tlc){

        this.Intid = id;

        this.UpdateCount = updCount ?? 0;

        this.Tlc = tlc;

    }

}

​

public class HelloWorld

{

    public static void Main(string[] args)

    {

        var startDate = DateTime.Now;

        var endDate = startDate;

        Console.WriteLine("Creating list of results...");

        var listOfItems = CreateListOfSearchResults(100000);

        startDate = DateTime.Now;

        var newList = RemoveDupesFromSearchResult_UsingLINQ(listOfItems);

        endDate = DateTime.Now;

        Console.WriteLine("RemoveDupesFromSearchResult_UsingLINQ took: {0:N6}ms", (endDate - startDate).Milliseconds);

        startDate = DateTime.Now;

        newList = RemoveDupesFromSearchResult_UsingDictionary(listOfItems);

        endDate = DateTime.Now;

        Console.WriteLine("RemoveDupesFromSearchResult_UsingDictionary took: {0:N6}ms", (endDate - startDate).Milliseconds);

    }

    private static List<SearchResultRow> CreateListOfSearchResults(int qty = 100){

        var list = new List<SearchResultRow>();

        for(var i = 0; i < qty;i++){

            list.Add(new SearchResultRow(i +1, 0, null));

        }

        return list;

    }

    private static List<SearchResultRow> RemoveDupesFromSearchResult_UsingLINQ(List<SearchResultRow> searchResult)

    {

        return searchResult.DistinctBy(t => t.Intid).ToList();

    }

    private static List<SearchResultRow> RemoveDupesFromSearchResult_UsingDictionary(List<SearchResultRow> searchResult)

    {

        var distinctList = new Dictionary<int, SearchResultRow>();

        foreach (var item in searchResult)

        {

            distinctList[item.Intid] = item;

        }

        return distinctList.Values.ToList();

    }

}