780B Problem Set 8- Binary Search Tree Solution

Problem Set 8: Binary Search Tree

Binary search trees (BST) are used to efficiently store data in a quickly searchable structure. In this assignment, we will create a generalized BST and then use it to perform a word count on a text document. I’ve also added a simple word cloud in OpenGL using the data stored in the BST.
Since you are spending more time on the team project, I want to keep this assignment considerably less “rigorous”. Start by downloading the incomplete project code attached to this assignment. If using MacOS, be sure to use the correct version of the graphic library files (fssimplewindow and yspng, specially).
Note that the C++ compiler needs to have access to the function definitions at compile time and thus it is best if the whole entire template class (declarations and definitions) is contained within the .h file. The project contains the start of the BST code and a main() source file that does a lot of the work of reading the text and handling graphics.
Once downloaded, you need to fill in the code needed for BST::insertItem(), BST::printInOrder(), BST::findItem(), and BST::retrieveItemCount(). We will work on BST::deleteItem() together so we can get a feel for how pointers and recursion can work.
Note that the tree is implemented as a collection of nodes, each with pointers to the left and right child nodes. Both the tree and the nodes are defined as template classes.

Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.
Now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and so dedicated, can long endure. We are met on a great battlefield of that war. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live. It is altogether fitting and proper that we should do this.
But, in a larger sense, we cannot dedicate, we cannot consecrate, we cannot hallow, this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great task remaining before us, that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion, that we here highly resolve that these dead shall not have died in vain, that this nation, under God, shall have a new birth of freedom, and that government of the people, by the people, for the people, shall not perish from the earth.
Abraham Lincoln



Word Cloud
I used the word frequency developed using the BST to create a very, very simple word cloud, making use of the GraphicFont library I developed (which is included in the zipped project file).
Note that the word cloud used in the title above requires that the placement of each word be perfectly located based on pixel reasoning so that the cloud can fill in tiny spaces between words. I did not accomplish this level of sophistication for this assignment. Instead, I created a word cloud using the following simple rules:
• Words whose count is 1 will be shown only if user asks for them
• Some common words (e.g., “the”, “a”, “and”, etc.) can also be omitted.
• Whatever size (S) is selected for words with a count of 1, the size is increased by a factor for each increase (e.g., 2S, 3S, 4S, 5S, 5S, and 6S for word counts of 2, 3, 4, 5, and 6)
• The location of each word is randomly selected for each word (i.e., random X, random Y).
• The transparency of each word to about 0.6 so that you can see words that are covered up.
• The colors can be randomized (i.e., rainbow)

Feel free to play around with the graphics so you get to understand how it all works.

Deliverables
1 zip file, containing your whole project. I advise that you include your name in comments at the top of each of the files. I expect your project will at least include the following:
wordCloud_main_andrewID.cpp << contains main() and some other code
BST_andrewID.h << contains your new code as well as mine

Learning Objectives
Template classes in C++
Using Binary Search Trees.
Reading and writing to files.
Use OpenGL primitives along with code written by others.
Searching references (online or textbook) for C++ library functions.