Given the interface "BigNumberInterface.java" and the application "BigNumberApplication.java",

implement the class "BigNumberImplementation.java" that can be used for addition,subtraction of real values that can have up to 100 digits.

- BigNumberInterface.java

package reviewAbstractionInterfaceImplementationPackage.interfaces;

public interface BigNumberInterface { BigNumberInterface add (BigNumberInterface o); BigNumberInterface sub (BigNumberInterface o); }

- BigNumberApplication.java

package reviewAbstractionInterfaceImplementationPackage.applications;

import reviewAbstractionInterfaceImplementationPackage.implementations.BigNumberImplementation; import reviewAbstractionInterfaceImplementationPackage.interfaces.BigNumberInterface;

public class BigNumberApplication {

public static void main(String[] args) { BigNumberInterface n1 = new BigNumberImplementation(0.123456789012345678); BigNumberInterface n2 = new BigNumberImplementation(0.123456789012345678); BigNumberInterface sum, diff; sum = n1.add(n2); diff = n1.sub(n2); System.out.println("Sum = " + sum); System.out.println("Diff = " + diff); }

}

- BigNumberImplementation.java

package reviewAbstractionInterfaceImplementationPackage.implementations;

import reviewAbstractionInterfaceImplementationPackage.interfaces.BigNumberInterface;

public class BigNumberImplementation implements BigNumberInterface { private double value;

public BigNumberImplementation(double value) { // TODO Auto-generated constructor stub this.value = value; }

@Override public BigNumberInterface add(BigNumberInterface o) { BigNumberImplementation sum = new BigNumberImplementation(0); sum.value = this.value + ((BigNumberImplementation) o).value; return sum; }

@Override public BigNumberInterface sub(BigNumberInterface o) { BigNumberImplementation sum = new BigNumberImplementation(0); sum.value = this.value - ((BigNumberImplementation) o).value; return sum; }

@Override public String toString() { return ""+ value; }

}