using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public class Row

    {

        public int run;

        public int employee;

        public int employment;

        public int value;

    }

    public static void Main()

    {

        List<Row> rows = new List<Row>(){

            new Row(){run=1,employee=9,employment=9, value = 1},

            new Row(){run=5,employee=9,employment=9, value = 2},

            new Row(){run=5,employee=9,employment=9, value = 3},

            new Row(){run=3,employee=11,employment=11, value = 4},

            new Row(){run=4,employee=11,employment=11, value = 5}

        };

​

        var result = rows.GroupBy(r => new { r.employee, r.employment })

            .SelectMany(g => g.GroupBy(r => r.run).OrderByDescending(d => d.Key).First());

​

        var i = 0;

        foreach (var r in result)

        {

            Console.WriteLine("result: {0}: run:{1} employee:{2} employment:{3} value:{4}", i, r.run, r.employee, r.employment, r.value);

            i++;

        }

        var result2 = rows.GroupBy(r => new { r.employee, r.employment })

            .SelectMany(g => g.GroupBy(r => r.run).OrderByDescending(d => d.Key).First())

            .GroupBy(r => new { r.employee, r.employment });

​

        i = 0;

        foreach (var r in result2)

        {

            var key = r.Key;

            foreach (var c in r)

            {

                Console.WriteLine("result2: {0}: run:{1} employee:{2} employment:{3} value:{4}", i, c.run, key.employee, key.employment, c.value);

            }

            i++;

        }

​

        Console.ReadLine();

    }

}