using System;

using System.Linq;

using System.Collections.Generic;

class Dev

{ 

    public bool HasChildren; 

    public string FirstName ; 

    public int BBGamesWatched;

}

​

public class Program

{

    public static void Main()

    {

        List<Dev> devs = new List<Dev>()

        {

            new Dev { FirstName = "Brenda", HasChildren = true, BBGamesWatched = 3},

            new Dev { FirstName = "Julian", HasChildren = false, BBGamesWatched = 2},

            new Dev { FirstName = "Yousef", HasChildren = false, BBGamesWatched = 4},

            new Dev { FirstName = "Nelson", HasChildren = true, BBGamesWatched = 2},

            new Dev { FirstName = "Phil", HasChildren = true, BBGamesWatched = 1},

            new Dev { FirstName = "Tim", HasChildren = true, BBGamesWatched = 5},

            new Dev { FirstName = "Julia", HasChildren = false, BBGamesWatched = 0},

            new Dev { FirstName = "Andrea", HasChildren = false, BBGamesWatched = 1},

            new Dev { FirstName = "Chetna", HasChildren = false, BBGamesWatched = 2},

        };

        //Group devs by whether they have children.

        var kidsResults = devs.GroupBy(dev => dev.HasChildren, dev => dev.FirstName, (key, g) => new {HasKids=key, Names = g.ToList()});

        foreach(var item in kidsResults){

            Console.WriteLine(item.HasKids ? "Has Kids:" : "No Kids:");

            foreach(string name in item.Names) {

                Console.WriteLine(name);

            }

            Console.WriteLine(" ");

        }

        Console.WriteLine("-------------------");

        //Group devs by name length and order groups by ascending length. Within each group, order names alphabetically.

        //x=>x: identity

        var lengthResults = devs.GroupBy(dev => dev.FirstName.Length, dev => dev.FirstName, (key, people) => new {NameLength=key, Names = people.OrderBy(x=>x).ToList()}).OrderBy(g => g.NameLength);

        foreach(var item in lengthResults){

            Console.WriteLine("Name Length: " + item.NameLength);

            foreach(string name in item.Names) {

                Console.WriteLine(name);

            }

            Console.WriteLine(" ");

        }

        Console.WriteLine("-------------------");

        //Aggregate the number of baseball games the devs have watched.

        //Func<int, Dev> sumOfGames = (TotalGames, dev) => TotalGames += dev.BBGamesWatched;

        //Select = map; Aggregate = Reduce; Sum is a type of reduce

        int gamesResults = devs.Select(dev => dev.BBGamesWatched).Sum();

        //int gamesResults = devs.Aggregate<Dev, int>(0, sumOfGames);

        //for loop doing the same thing

        //TotalGames: accumulator

        //reducing list to single value

        Console.WriteLine("Total games watched: " + gamesResults);

​

    }

}