using System;

​

/*

Task:

Implement an AdvancedCalculator class with the following methods:

​

        1. Add(int a, int b): int - This method should return the sum of 

        two integers.

​

        2. Subtract(int a, int b): int - This method should return the 

        result of subtracting the second integer from the first.

​

        3. Multiply(int a, int b): int - This method should return the 

        product of two integers.

​

        4. Divide(int a, int b): double - This method should return the

        result of dividing the first integer by the second as a double.

​

        5. Power(int base, int exponent): double - This static method 

        should return the result of raising the base to the power of 

        the exponent.

​

        6. ApplyOperation(int a, int b, IOperation operation): double - This 

        method should take two integers and an object that implements the 

        IOperation interface. It should apply the operation defined by the 

        IOperation object to the two integers.

    Implement the IOperation interface with a method:

    public interface IOperation

    {

        int Operate(int a, int b);

    }

    Create a class CustomOperation that implements the IOperation interface. 

    This class should perform a custom operation on the two integers 

    (for example, concatenating them as strings and converting back to an integer).

*/

​

/////////////////////////////////////////////////////////////////////////

// Your task is to create the AdvancedCalculator, IOperation interface, 

// and CustomOperation class, and implement the above methods to achieve 

// the expected results.

​

// ***** write class/interface here *******

public interface IOperation

{

    int Operate(int a, int b);

}

​

public class CustomOperation : IOperation

{

    public int Operate(int a, int b)

    {

        return int.Parse(a.ToString() + b.ToString());

    }

}

​

public interface IAdvancedCalculator

{

    int Add(int a, int b);

    int Subtract(int a, int b);

    int Multiply(int a, int b);

    double Divide(int a, int b);

    static abstract double Power(int @base, int exponent);

    double ApplyOperation(int a, int b, IOperation operation);

}

​

public class AdvancedCalculator : IAdvancedCalculator

{

    public int Add(int a, int b)

    {

        return a + b;

    }

​

    public int Subtract(int a, int b)

    {

        return b - a;

    }

​

    public int Multiply(int a, int b)

    {

        return a * b;

    }

​

    public double Divide(int a, int b)

    {

        return (double)a / b;

    }

​

    public static double Power(int @base, int exponent)

    {

        return Math.Pow(@base, exponent);

    }

​

    public double ApplyOperation(int a, int b, IOperation operation)

    {

        return operation.Operate(a, b);

    }

}

​

// ****************************************

​

public class Program

{

    public static void Main()

    {

        IAdvancedCalculator calculator = new AdvancedCalculator();

        Console.WriteLine(calculator.Add(1, 2));

        Console.WriteLine(calculator.Subtract(1, 2));

        Console.WriteLine(calculator.Multiply(5, 2));

        Console.WriteLine(calculator.Divide(1, 2));

        Console.WriteLine(AdvancedCalculator.Power(2, 2));

        Console.WriteLine(calculator.ApplyOperation(4, 4, new CustomOperation()));

    }

}