Homework #2

Due June 28, by 11:59:59 pm – Electronic submission

Question one (100 points)

In ADA, you are to build a prefix to postfix converter. You will be given an input file with expressions in prefix notation and you will need to build an expression tree for each expression. You will then output each equivalent postfix expression to a file.

Things you need to look up/brush up on:

· Trees

· Tree Traversal

· Input/Output to Files

· Parsing Input

Work on the problem in steps. While this is one problem to solve, each intermediate problem is worth some points. The file input/output working, constructing the tree, etc.

Assume that the file will consist of one or more lines, with each line containing a prefix expression. Each component of the expression will be separated by a space, for easier parsing. Example:

* 7 8

* 78 9

+ - 6 5 34

Valid operators include addition (+), subtraction (-), multiplication (*), and division (/). Your output file should be constructed with the same format. For simplicity, you may hardcode the names of your input and output files within your program (but do indicate the names of the files in the header comments of your program for grading purposes).

We will discuss the basic algorithms for tree traversal in class, and will discuss how to create such a structure.

Name your program HW2.adb and submit using the electronic submission program:

submit_cse305 HW2.adb

If you are using more than one file, make sure you zip them and call the zip HW2.zip. If there are special instructions, please include a file named README. Please follow the naming conventions. Failure to do so will cause your assignment to not be graded.