using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        int[] awesomeNumbers = {4,2,49,21,92,39,10,08,73,94,81,95,14};

        string[] emptyBasket = {};

        string[] fruits = {"apple", "mango", "yakfruit", "canneryfruit", "orange", "passionfruit", "grape", "pear"};

        string[] fruits2 = {"apple", "yakfruit", "orange", "grape", "pear", "watermelon"};

        string[] largeFruits = {"watermelon", "papaya", "dragonfruit", "jackfruit"};

        string[] grape = {"grape"};

        int[] emptyArray = {};

        // Order Tenants by Building # then by number of Pets

        // Create Tenants

        List<Tenant> allTenants = new List<Tenant>();

        Tenant Jash = new Tenant("Jash", 2, new List<Pet>{

            new Pet{Name = "Bonkers", Age = 3}

        });

        Tenant Dave = new Tenant("Dave", 1, new List<Pet>{

            new Pet{Name = "Tim", Age = 34},

            new Pet{Name = "Smedge", Age = 2},

        });

        Tenant Samantha = new Tenant("Samantha", 1, new List<Pet>{

            new Pet{Name = "Rex Goliath", Age = 6}

        });

        Tenant Poti = new Tenant("Poti", 1, new List<Pet>{

            new Pet{Name = "Jem", Age = 2},

            new Pet{Name = "Egg", Age = 23},

            new Pet{Name = "Fluffy the Warrior", Age = 9}

        });

        allTenants.Add(Jash);

        allTenants.Add(Dave);

        allTenants.Add(Samantha);

        allTenants.Add(Poti);

        IEnumerable<Tenant> firstBuildingThenPetCount = allTenants.OrderBy(thisTenant => thisTenant.BuildingNumber).ThenBy(thisTenant => thisTenant.PetList.Count);

        foreach (Tenant tenant in firstBuildingThenPetCount){

            Console.WriteLine(tenant.Name); 

            Console.WriteLine(" --Pets: " + String.Join(" | ", tenant.PetList.Select(thisPet => thisPet.Name + "(" + thisPet.Age + ")") ));

        }

        Console.WriteLine();

        // Order fruits by their last letter then by length, longest first

        IEnumerable<string> weirdFruitOrder = fruits.OrderBy(thisFruit => thisFruit.Last()).ThenByDescending(thisFruit => thisFruit.Length);

        Console.WriteLine("fruits by their last letter then by length, longest first");

        Console.WriteLine("Fruits: " + String.Join(" ", weirdFruitOrder));

        Console.WriteLine();

        Console.WriteLine("---");

        // Example from Microsoft Docs https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.thenby?view=netcore-3.1

        string[] MSfruits = { "grape", "passionfruit", "banana", "mango", 

                      "orange", "raspberry", "apple", "blueberry" };

        IEnumerable<string> query =

        MSfruits.OrderBy(fruit => fruit.Length).ThenBy(fruit => fruit);

​

        foreach (string fruit in query)

        {

            Console.WriteLine(fruit);

        }

    }

}

class PetOwner

{

    public string Name { get; set; }

    public List<string> Pets { get; set; }

}

​

public class Pet

{

    // Attributes

    public string Name{ get; set;}

    public int Age{ get; set;}

    // Constructors

    public Pet(){}

    public Pet(string n, int a){

        this.Name = n;

        this.Age = a;

    }

}

​

// Custom Comparer for Pet Class

public class PetComparer : IEqualityComparer<Pet>

{

    public bool Equals(Pet x, Pet y){

        //Check whether the compared objects reference the same data.

        if (Object.ReferenceEquals(x, y)) return true;

​

        //Check whether any of the compared objects is null.

        if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))

            return false;

​

        //Check whether the products' properties are equal.

        return x.Name == y.Name && x.Age == y.Age;

    }

    // If Equals() returns true for a pair of objects 

    // then GetHashCode() must return the same value for these objects.

    public int GetHashCode(Pet pet){

        //Check whether the object is null

        if (Object.ReferenceEquals(pet, null)) return 0;

​

        //Get hash code for the Name field if it is not null.

        int hashProductName = pet.Name == null ? 0 : pet.Name.GetHashCode();

​

        //Get hash code for the Age field.

        int hashProductAge = pet.Age.GetHashCode();

​

        //Calculate the hash code for the product.

        return hashProductName ^ hashProductAge;

    }

}

​

public class Building

{

    // Attributes

    public string Name{ get; set;}

    public string Address{ get; set;}

    public int Number{ get; set;}

    // Constructors

    public Building(){}

    public Building(string name, string addy, int num){

        this.Name = name;

        this.Address = addy;

        this.Number = num;

    }

}

​

public class Tenant

{

    // Attributes

    public string Name{ get; set;}

    public int BuildingNumber{ get; set;}

    public List<Pet> PetList{get; set;}

    // Constructors

    public Tenant(){}

    public Tenant(string name, int BN){

        this.Name = name;

        this.BuildingNumber = BN;

        this.PetList = new List<Pet> {};

    }

    public Tenant(string name, int BN, List<Pet> PL){

        this.Name = name;

        this.BuildingNumber = BN;

        this.PetList = PL;

    }

}

​

public class Product

{

    // Attributes

    public string Name { get; set; }

    public int Code { get; set; }

    // Constructors

    public Product(){}

    public Product(string n, int c){

        this.Name = n;

        this.Code = c;

    }

}

​

// Custom comparer for the Product class

class ProductComparer : IEqualityComparer<Product>

{

    // Products are equal if their names and product numbers are equal.

    public bool Equals(Product x, Product y)

    {

        //Check whether the compared objects reference the same data.

        if (Object.ReferenceEquals(x, y)) return true;

​

        //Check whether any of the compared objects is null.

        if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))

            return false;

​

        //Check whether the products' properties are equal.

        return x.Code == y.Code && x.Name == y.Name;

    }

​

    // If Equals() returns true for a pair of objects 

    // then GetHashCode() must return the same value for these objects.

​

    public int GetHashCode(Product product)

    {

        //Check whether the object is null

        if (Object.ReferenceEquals(product, null)) return 0;

​

        //Get hash code for the Name field if it is not null.

        int hashProductName = product.Name == null ? 0 : product.Name.GetHashCode();

​

        //Get hash code for the Code field.

        int hashProductCode = product.Code.GetHashCode();

​

        //Calculate the hash code for the product.

        return hashProductName ^ hashProductCode;

    }

}