Starting from:

$25

Create a program that will evaluate mathematical expressions like

General Instructions Create a program that will evaluate mathematical expressions like 23 − 2 ∗ 5 4 − 9 ∗ 11 + 155 ∗ ( 21 − 17 ) / 3 ( ( 15 / ( 7 − ( 1 + 1 ) ) ) − ( 2 + ( 1 + 1 ) ) and determines their value. Special Instructions Input File Your program is given the name of the input text file. The text file contains mathematical expressions (like the ones above). There is always only one expression per line. Each valid expression consists of tokens separated by one or more spaces. A token is either an integer, an operator (+,-,*,/), or an open or a closed parenthesis. If the filename is omitted, it is an error. If the filename is given but it does not exist or cannot be opened for reading by the program, for any reason, it is an error. The program should display an error message if any of these conditions occur, and it should be as specific as possible (it is not enough for it to say “could not open file”). Your program is NOT ALLOWED to hardcode the input filename in its own code. Output File Your program is given the name of the output text file. As your program evaluates each of the expressions in the input file, the results of computations should be printed to the output time. If a corresponding expression in the input file is not valid, your program should print INVALID instead of the result and continue with the next expression. The results should be printed one per line. If the filename is omitted from the command line, it is an error. If the filename is given but it does not exist or cannot be opened for reading by the program, for any reason, it is an error. The program should display an error message if any of these conditions occur, and it should be as specific as possible (it is not enough for it to say “could not open file”). Your program is NOT ALLOWED to hardcode the input filename in its own code. User Input This program is not interactive. Program Design Your program must contain multiple classes and must be developed in an object oriented way. You will need to develop the following classes: ConsoleCalculator - the class that provides the main() method. This class is responsible for all input and output operations (including validation of the input). ExpressionTools - the class that provides the methods for infix to postfix conversion and for postfix evaluation. Stack - the class that provides an array based implementation of the stack we covered in class. PostFixException - the class that represent the exception that should be thrown when errors in the expression occur. The program should read each of the expressions from the input file, convert it to the postfix expression, evaluate the postfix expression and print the result to the output file. Converting From Infix to Postfix The algorithm for converting the infix expressions to postfix expressions is as follows: If any errors are encountered, your method should throw an exception of type PostFixException with an appropriate message. If any errors are encountered, your method should throw an exception of type PostFixException with an appropriate message.

More products