using System;

using System.Collections.Generic;

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public class Program

{

    public static void Main()

    {

        var goals = new List<Goal>();

        goals.Add(new Goal(){ID=1, Level=1, Active = true});

        goals.Add(new Goal(){ID=2, Level=1, Active = false});

        goals.Add(new Goal(){ID=3, Level=2, Active = true});

        goals.Add(new Goal(){ID=4, Level=2, Active = true});

        goals.Add(new Goal(){ID=5, Level=2, Active = false});

        goals.Add(new Goal(){ID=6, Level=2, Active = false});

        goals.Add(new Goal(){ID=7, Level=2, Active = false});

        goals.Add(new Goal(){ID=8, Level=2, Active = false});

        goals.Add(new Goal(){ID=9, Level=2, Active = false});

        goals.Add(new Goal(){ID=10, Level=2, Active = true});

        goals.Add(new Goal(){ID=11, Level=2, Active = true});

        goals.Add(new Goal(){ID=12, Level=2, Active = true});

        goals.Add(new Goal(){ID=13, Level=2, Active = true});

        goals.Add(new Goal(){ID=14, Level=2, Active = true});

        goals.Add(new Goal(){ID=15, Level=2, Active = true});

        goals.Add(new Goal(){ID=16, Level=2, Active = true});

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        Random rnd = new Random();

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        Comparison<Goal> comparison =  (a, b) => {

             // first chooses the Active ones (if any)

             var sort = b.Active.CompareTo(a.Active);

           if (sort == 0) {

            // then sort by level

            return sort = (a.Level).CompareTo(b.Level);

            } else 

           {

               return sort;

           }

         };

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        goals.Sort(comparison);

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        int startIndex = 0;

        int endIndex = 0;

        while (startIndex < goals.Count)

        {

            for (endIndex = startIndex + 1; endIndex < goals.Count; ++endIndex)

            {

                if (comparison(goals[startIndex], goals[endIndex]) != 0)

                {

                    //End of tie

                    break;

                }

            }

            if (endIndex - startIndex > 1)

            {

                ShuffleRange(goals, startIndex, endIndex - startIndex, rnd);

            }

            startIndex = endIndex;

        }   

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        foreach(var g in goals)

        {

           Console.WriteLine("ID={0:00}, Level={1}, Active={2}", g.ID, g.Level, g.Active);             

        }

    }

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    static void ShuffleRange<T>(List<T> list, int startIndex, int count, Random rnd)

    {

         int n = startIndex + count;  

         while (n > startIndex + 1) 

         {  

            int k = rnd.Next(startIndex, n--);  

            T value = list[k];  

            list[k] = list[n];  

            list[n] = value;  

        }  

    }

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}

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    public class Goal {

      public int ID;

      public int Level;

    public bool Active;

}

​