FSU COP 4530 / CGS 5425 (Fall 2003)
Data Structures, Algorithms, and Generic Programming
Assignment 4: Reverse Polish Calculator (Due 10/31/2003)
Teaching assistants
Zhiqian Hu (zhiqiahu@cs.fsu.edu) Nobuyasu Fukuhara (nff0150@garnet.acns.fsu.edu)
Office: CS Majors Lab Office: CS Majors Lab
Office hours: T 3:00pm 5:00pm Office hours: W 1:00pm 3:00pm
Educational Objectives: Apply the STL stack data structure and the queue data structure to the fundamental concept of computing. Become familiarized with the postfix notation as the prelude for the tree data structure.
Assignment: Write a program that takes a human readable mathematical equation, converts it into a postfix equation, and evaluates the postfix equation.
Deliverables: Turn in makefile, and all header and cpp files, using project4submit.sh (due 10/31). At each lecture, you need to turn in a hardcopy of your cumulative development log. For each day that you worked, please list the features you implemented, bugs you fixed, and the help you obtained from others.
Requirements:
1. Create a subdirectory called proj4. Make sure that your code distribution directories are up to date by invoking your update command.
2. Your makefile, header files, and source files should be placed in the proj4 directory.
3. You must use the Standard Template Library's queue and stack classes for this assignment.
4. Your program should handle digits, (, ), and the following operators: +, -, *, /.
5. Whitespaces should be ignored.
6. Remember that ( and ) should have the highest precedence. For example, (1 + 2) * 3 should return 1 2 + 3 * as the postfix notation and 9 as the answer.
7. Remember that * and / should be evaluated before + and -. For example, 1 + 2 * 3 should return 1 2 3 * + as the postfix notation and 7 as the answer.
8. You dont need to handle broken or invalid equations (e.g., missing close parentheses).
9. Bonus (5pts): handle negative numbers. For example, 1 + (-2) should return 1 -2 + as the postfix notation and -1 as the answer. For -2 * 3, you program should return -2 3 * as the postfix notation and -6 as the answer.
10. The name of the executable is polish.
Sample Session:
Unix prompt> polish
Enter the human readable equation: (1 + 2) * 3
Postfix notation: 1 2 + 3 *
Answer: 9
Enter the human readable equation: 1 + 2 * 3
Postfix notation: 1 2 3 * +
Answer: 7
Enter the human readable equation: (4 + 2 * 5) / (1 + 3 * 2)
Postfix notation: 4 2 5 * + 1 3 2 * + /
Answer: 2
Enter the human readable equation: (2 * 5 + 4) / (3 * 2 + 1)
Postfix notation: 2 5 * 4 + 3 2 * 1 + /
Answer: 2
Bonus (5pts):
Write a program, prefix, that randomly generates valid prefix equations. Write a second program, human, that converts a prefix equation into a human readable equation.