CS 202, Fall 2007


Group Assignment #2: 10 Points.

Due Date: Thursday, 12/6/07.

        Submit one set of solutions for each group.  Each member of the
        group must contribute to the solutions submitted by the group.

(2)  1.	Modify the infix to postfix conversion program from Exercise 21.12
	to accept integer operands of any size within the range of standard
	4-byte integers.  Do this by inserting spaces into the postfix string 
	to separate numbers from operators.  Identify and document all changes 
	to the original code.  Test your modification thoroughly.**

(2)  2.	Modify the postfix evaluation program from Exercise 21.13 to accept 
 	postfix strings with integer operands of any size separated from 
	the operators by blank characters.  Do this by modifying the input
	function of the evaluator to use the strtok() function to extract
	the numbers and operators from a C-style postfix string (see pg 452).
	Then use the C atoi() function to convert strings of digits to their 
	numeric values.  Alternatively, rewrite the code to use C++ strings
	and member functions to tokenize and convert the postfix strings of
	digits to integers.  Identify and document all changes to the original 
	code.  Test your postfix evaluator using the test results from 
	Problem #1 above.**

(2)  3.	Combine the programs from Problems #1 and #2 above to produce a
	calculator program which allows you to enter an infix expression
	consisting of integer operands of any size and the operators +,-,
	*,/,% and ^.  Test the calculator on the same expressions used to
	test Problem #1.  Identify and document all changes to the original
	code.**

(4)  4.	Study the description of the Simple compiler in Exercise 21.27.
	Build the Simple language compiler found in the textbook ch21 folder 
	p21_27.  Test the compiler by compiling the Simple factorial program 
	from Problem 3, HW#10 into SML.  Execute the SML file using the 
	Simpletron simulator from Problem 1, HW#7.  Extra credit will be 
	given for fully documented bug fixes to the original compiler code.**


      **For full credit, turn in fully commented program listings,
	including your name and the problem number, and the output
	from test runs exactly as produced by the program.