This question involves computing an integer based on two input strings. You will write the compute method

of the following Operator class.

public class Operator

$\{$

$/**$ Returns an integer value based on the input string $*/$

public static int transform$($String str$)$

$\{/*$ implementation not shown $*/\}$

$/**$ Returns an integer based on two input strings, as described in part

$($a$)$

$*$ Precondition Precondition: input and op are not null.

$*$ The length of input is even.

$*$ op is either $"$$$$","^^",$ or $"$##$".$

$*/$

public static int compute$($String input, String op$)$

$\{/*$ to be implemented in part $($a$)*/\}$

$//$ There may be variables and methods that are not shown.

$\}$

$($a$)$ Write the compute method of the Operator class. The method calculates an integer value based on an

input string with even length. The first half and the second half of input are transformed into numeric values

by calls to transform. The numeric values are then used in a calculation based on the mathematical operation

represented by the string, op$.$ The method returns the calculated result.

The helper method transform has been provided. The method returns an integer value based on its String

parameter. For example, the method call transform$("$pear$")$ might return the int value $3.$

The mathematical operations represented by op are described in the following table. Assume that value$1$ is

the numeric value obtained by calling transform on the first half of input and value$2$ is the numeric

value obtained by calling transform on the second half of input.