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 = {};

        // Compare fruits and fruits2

        bool fruitsFruits2AreEqual = fruits.SequenceEqual(fruits2);

        Console.WriteLine("The fruits and fruits2 arrays {0} equal to each other.", fruitsFruits2AreEqual ? "are" : "are not");

        Console.WriteLine();

        // Compare largeFruits and a new string array

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

        bool largeFruitCompare = largeFruits.SequenceEqual(otherLargeFruits);

        Console.WriteLine("The largeFruits and otherLargeFruits arrays {0} equal to each other.", largeFruitCompare ? "are" : "are not");

        Console.WriteLine();

        // Check to see if 2 pet lists are the same

        Pet chuck = new Pet { Name = "Charles", Age = 6 };

        Pet pete = new Pet { Name = "Pete", Age = 2 };

        Pet alsoCharles = new Pet { Name = "Charles", Age = 6 };

        List<Pet> twoChuck1 = new List<Pet>();

        twoChuck1.Add(chuck);

        List<Pet> twoChuck2 = new List<Pet>();

        twoChuck2.Add(chuck);

        bool twoChuckEqual = twoChuck2.SequenceEqual(twoChuck1);

        Console.WriteLine("twoChuckEqual: " + twoChuckEqual);

        // Check on 2 pet lists with different inputs

        // Order matters

        List<Pet> chuckAndCharles1 = new List<Pet>();

        chuckAndCharles1.Add(chuck);

        chuckAndCharles1.Add(new Pet("Pete", 2));

        List<Pet> chuckAndCharles2 = new List<Pet>();

        chuckAndCharles2.Add(alsoCharles);

        chuckAndCharles2.Add(pete);

        // These are not equal because their references are not the same

        bool chuckAndCharlesEqual = chuckAndCharles1.SequenceEqual(chuckAndCharles2);

        Console.WriteLine("chuckAndCharlesEqual: " + chuckAndCharlesEqual);

        // Add the IEqualityComparer

        bool chuckAndCharlesEqualWithIEqualityComparer = chuckAndCharles1.SequenceEqual(chuckAndCharles2, new PetComparer());

        Console.WriteLine("chuckAndCharlesEqualWithIEqualityComparer: " + chuckAndCharlesEqualWithIEqualityComparer);

        Console.WriteLine();

        Console.WriteLine("---");

        // Example from Microsoft Docs https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.sequenceequal?view=netframework-4.8

        Pet pet1 = new Pet { Name = "Turbo", Age = 2 };

        Pet pet2 = new Pet { Name = "Peanut", Age = 8 };

​

        // Create two lists of pets.

        List<Pet> pets1 = new List<Pet> { pet1, pet2 };

        List<Pet> pets2 = new List<Pet> { pet1, pet2 };

​

        bool equal = pets1.SequenceEqual(pets2);

​

        Console.WriteLine(

        "The lists {0} equal.",

        equal ? "are" : "are not");

        Console.WriteLine();

        Pet pet1m = new Pet() { Name = "Turbo", Age = 2 };

        Pet pet2m = new Pet() { Name = "Peanut", Age = 8 };

​

        // Create two lists of pets.

        List<Pet> pets1m = new List<Pet> { pet1, pet2 };

        List<Pet> pets2m =

        new List<Pet> { new Pet { Name = "Turbo", Age = 2 }, 

                        new Pet { Name = "Peanut", Age = 8 } };

​

        bool equalM = pets1m.SequenceEqual(pets2m);

​

        Console.WriteLine("The m lists {0} equal.", equalM ? "are" : "are not");

        Console.WriteLine("");

        // Prodcut Comparer from Microsoft

        Product msOrange = new Product("orange", 4);

        List<Product> storeA = new List<Product> { new Product { Name = "apple", Code = 9 }, 

                       new Product { Name = "orange", Code = 4 } };

​

        List<Product> storeB = new List<Product> { new Product { Name = "apple", Code = 9 }};

        storeB.Add(msOrange);

​

        bool equalAB = storeA.SequenceEqual(storeB, new ProductComparer());

​

        Console.WriteLine("StoreA and StoreB Equal? " + equalAB);

    }

}

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;

    }

}