# Write a program that evaluates infix expressions of unsigned integers using two stacks...

Write a program that evaluates infix expressions of unsigned integers using two stacks. The program should consist of three classes. The main class should create a GUI that allows the user input an infix expression and displays the result. The GUI should look as follows (please see attached file):

The GUI must be generated by code that you write. You may not use a drag-and-drop GUI

generator.

The second class should contain the code to perform the infix expression evaluation. The

pseudocode for performing that evaluation is shown below:

tokenize the string containing the expression

while there are more tokens

get the next token

if it is an operand

push it onto the operand stack

else if it is a left parenthesis

push it onto the operator stack

else if it is a right parenthesis

while top of the operator stack not a left parenthesis

pop two operands and an operator

perform the calculation

push the result onto the operand stack

else if it is an operator

while the operator stack is not empty and

the operator at the top of the stack has higher

or the same precedence than the current operator

pop two operands and perform the calculation

push the result onto the operand stack

push the current operator on the operators stack

while the operator stack is not empty

pop two operands and an operator

perform the calculation

push the result onto the operand stack

the final result is a the top of the operand stack

Be sure to add any additional methods needed to eliminate any duplication of code.

Your program is only expected to perform correctly on syntactically correct infix expressions

that contain integer operands and the four arithmetic operators + - * /. It should not,

however, require spaces between tokens. The usual precedence rules apply. The division

performed should be integer division. A check should be made for division by zero. Should the

expression contain division by zero, a checked exception DivideByZero should be thrown by

the method that performs the evaluation and caught in the main class, where a JOptionPane

window should be displayed containing an error message.

The GUI must be generated by code that you write. You may not use a drag-and-drop GUI

generator.

The second class should contain the code to perform the infix expression evaluation. The

pseudocode for performing that evaluation is shown below:

tokenize the string containing the expression

while there are more tokens

get the next token

if it is an operand

push it onto the operand stack

else if it is a left parenthesis

push it onto the operator stack

else if it is a right parenthesis

while top of the operator stack not a left parenthesis

pop two operands and an operator

perform the calculation

push the result onto the operand stack

else if it is an operator

while the operator stack is not empty and

the operator at the top of the stack has higher

or the same precedence than the current operator

pop two operands and perform the calculation

push the result onto the operand stack

push the current operator on the operators stack

while the operator stack is not empty

pop two operands and an operator

perform the calculation

push the result onto the operand stack

the final result is a the top of the operand stack

Be sure to add any additional methods needed to eliminate any duplication of code.

Your program is only expected to perform correctly on syntactically correct infix expressions

that contain integer operands and the four arithmetic operators + - * /. It should not,

however, require spaces between tokens. The usual precedence rules apply. The division

performed should be integer division. A check should be made for division by zero. Should the

expression contain division by zero, a checked exception DivideByZero should be thrown by

the method that performs the evaluation and caught in the main class, where a JOptionPane

window should be displayed containing an error message.

You'll get a 1.7KB .ZIP file.