using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    static List<ContentModel> contentOptions = new List<ContentModel>

    {

        new ContentModel

        {

            Content = "hello",

            Weight = 20

        },

            new ContentModel

        {

            Content = "hey",

            Weight = 80

        },

            new ContentModel

        {

            Content = "yo dawg",

            Weight = 90

        }

    };

    public static void Main(string[] args)

    {

        List<string> selectedGreetings = new List<string>();

        GetNextGreeting()

            .Take(1000)

            .GroupBy(x => x)

            .Select(x => new { Count = x.Count(), Content = x.Key })

            .ToList()

            .ForEach(x => Console.WriteLine("{0} : {1}", x.Content, x.Count));

    }

    static IEnumerable<string> GetNextGreeting()

    {

        Random generator = new Random();

        while (true)

        {

            int totalWeight = contentOptions.Sum(x => x.Weight);

            int selection = generator.Next(0, totalWeight);

            foreach (ContentModel model in contentOptions)

            {

                if (selection - model.Weight > 0)

                    selection -= model.Weight;

                else

                {

                    yield return model.Content;

                    break;

                }

            }

        }

    }

}

​

class ContentModel

{

    public string Content { get; set; }

    public int Weight { get; set; }

}

​