CPSC 223 Homework 5

CPSC 223: Homework 5. Cloud - word cloud generator

Due 2:00 AM, Friday, 7 April 2017 (one week extension)

P R E L I M I N A R Y S P E C I F I C A T I O N

REMINDER: Do not under any circumstances copy another student's code or give a copy of your code to another student. After discussing the assignment with another student, you may not take any written or electronic record away. Moreover, you must engage in a full hour of mind-numbing activity before you work on it again. Such discussions must be noted in your log file.

A word cloud (or tag cloud) is a display of text in which the font size of a word is proportional to the frequency that the word occurs in a document.

Reading

See https://en.wikipedia.org/wiki/Tag_cloud
For examples, Google "word cloud" and click images.
Van Wyk Chapter 7: Searching
Aspnes: Binary Trees
Aspnes: Binary Search Trees

Program Specification

For this assignment, you will create a program:

  Cloud [-debug | -threshold value | -preorder | -inorder | -postorder | -html]

that reads standard input and writes to standard output. It tabulates the frequency that words occur in the input, and prints a list of those words that occur more than some threshold value.

Here are examples using piped input from echo:

% echo 'one two one two three four' | ./Cloud 
No words seen 5 times.
% echo 'one two one two three four' | ./Cloud -threshold 2
The Word Cloud:
[0] two [2]
[1] one [2]
% echo 'One 1 Two One. one two three four' | ./Cloud -threshold 2
The Word Cloud:
[0] two [2]
[1] one [2]

Note that the default value of threshold is 5. You can reset it with the -threshold command line argument. Also, Cloud converts uppercase letters to lowercase and ignores tokens that contain non-alpha characters, like "1" and "One."

% echo 'One 1 Two One. one two three four' | ./Cloud -inorder
INORDER
**root** [1 / 3] four [1 / 0] one [2 / 2] three [1 / 0] two [2 / 1] 
No words seen 5 times.
% echo 'One 1 Two One. one two three four' | ./Cloud -preorder
PREORDER
**root** [1 / 3] one [2 / 2] four [1 / 0] two [2 / 1] three [1 / 0] 
No words seen 5 times.
% echo 'One 1 Two One. one two three four' | ./Cloud -postorder
POSTORDER
four [1 / 0] three [1 / 0] two [2 / 1] one [2 / 2] **root** [1 / 3] 
No words seen 5 times.

Cloud stores the input words in a binary search tree, whose root node has the key value "**root**". Cloud will print out the values of the tree (including the frequency / height in square brackets) using preorder, inorder, or postorder traversal, depending on the respective command line arguments. Note that the inorder traversal is alphabetical order. Thus, the insert process should compare keys using alphabetical order with lowercase tokens.

If a command line argument occurs multiple times, there is no change in behavior, except that only the final threshold value is honored. If multiple traversal order arguments are present, the actual order will be preorder, inorder, and postorder.

As Cloud inserts elements in the binary search tree in the order in which they occur in the input, it checks to see if the word frequency has reached the threshold value. If so, it sticks the word node on the front of a linked list: cloud.

Here is an example using redirected input from a file:

% cat test2
I think that I shall never see a data structure as lovely as a tree
% ./Cloud -threshold 2 < test2
The Word Cloud:
[0] a [2]
[1] as [2]
[2] i [2]

Here is an example using the debug option:

% ./Cloud -threshold 2 -debug < test2
Input: I think that I shall never see a data structure as lovely as a tree
Tree height: 6
Tree size: 13
The Word Cloud:
[0] a [2]
[1] as [2]
[2] i [2]

If you give the -html argument, Cloud generates html code:

% cat test1
now is the time for all good men to come to the aid of their country
now is the time for all good men to come to the aid of their country
now is the time for all good men to come to the aid of their country
NOW is THE time For all good men to come to the aid of their country
NOW1 is, THE. time* For (all) 123  good men to come to the aid of their country
% cat test1 test1 test1 | ./Cloud -html 
<span style="font-size: 12px"> all </span>
<span style="font-size: 12px"> time </span>
<span style="font-size: 12px"> is </span>
<span style="font-size: 12px"> now </span>
<span style="font-size: 15px"> country </span>
<span style="font-size: 15px"> their </span>
<span style="font-size: 15px"> of </span>
<span style="font-size: 15px"> aid </span>
<span style="font-size: 15px"> come </span>
<span style="font-size: 15px"> men </span>
<span style="font-size: 15px"> good </span>
<span style="font-size: 15px"> for </span>
<span style="font-size: 30px"> to </span>
<span style="font-size: 27px"> the </span>

which is rendered as:
all time is now country their of aid come men good for to the

Here is a more impressive example.

% ./Cloudx -html < alice.txt > alice.html

We convert the entire text of Alice In Wonderland into a word cloud

Note that all words are separated by spaces. That allows you to use the C library function strtok(). You should ignore tokens containing punctuation or digits.

Also, all threshold values are integers. That allows you to use the C library function atoi().

Also, there will be no line splices in the input. That allows you to remain sane. Lines of input will not exceed 1024 characters.

All error output (usage and "Fatal Error" messages below) should be printed to standard error. For example,

   fprintf(stderr, "usage ...");

Note that not all errors are fatal. All other output should be printed to standard output. (Use normal printf.)

You may use global variables for threshold, debugflag, and cloud. Note that these are NOT defined in btree.h. Cloud should:

Implement a binary search tree. This is where you will store the words from the text. The header file btree.h is provided in /c/cs223/hw5. Implement btree.c. Do not modify btree.h Your code should refer to the btree.h in the hw5 directory:
```
  #include "/c/cs223/hw5/btree.h"
```
There are separate programs, /c/cs223/hw5/btreetest.c and /c/cs223/hw5/btreetestargs.c, which use this btree implementation. Your btree.c code should work with btreetest.c and btreetestargs.c. We may also use other programs to test your implementation of btree.c.
We will provide you a copy of btree.o so that you may test your Cloud.c program separately from implementing the btree.
Have no memory leaks. You will need to use dynamic memory allocation, e.g., malloc(). You want to make sure that you free up memory before termination. Use valgrind to detect any memory problems. It will also detect other kinds of memory lapses, such as reading or writing to unauthorized parts of memory.
Fail "gracefully" (i.e., neither go into an infinite loop nor cause a memory dump) if any of the assumptions above is violated.

Use the submit command (see below) to turn in the source file(s) for Cloud (e.g., Cloud.c, btree.c), a Makefile, and your log file (see below). Note: you should not submit btree.h. Your Cloud.c and btree.c file should have the following:

#include "/c/cs223/hw5/btree.h"

YOU MUST SUBMIT YOUR FILES (INCLUDING THE LOG FILE) AT THE END OF ANY SESSION WHERE YOU SPEND AT LEAST ONE-HALF HOUR WRITING OR DEBUGGING CODE, AND AT LEAST ONCE EVERY HOUR DURING LONGER SESSIONS. (All submissions are retained.)

Notes

When available, the public grading script will be /c/cs223/hw5/Tests/test.Cloud (and my solution will be /c/cs223/hw5/Cloudx). To run it, type
```
% /c/cs223/hw5/Tests/test.Cloud
```
You may invoke a given test as follows:
```
%  /c/cs223/hw5/Tests/test.Cloud 01
```
(you may specify more than one test here).
If your output looks the same as what is expected, but your program still fails the test, there are probably some invisible characters in your output.

Keep track of how you spend your time in completing this assignment. Your log file should be of the general form (that below is fictitious):

     ESTIMATE of time to complete assignment: 10 hours

           Time     Time
     Date  Started  Spent Work completed
     ----  -------  ----  --------------
     1/13  10:15pm  0:45  Read assignment and relevant material in K&R
     1/16   4:45pm  1:15  Sketched solution using a finite-state machine with
                            one-character look-ahead
     1/19   9:00am  2:20  Wrote the program and eliminated compile-time errors;
                            code passes eight tests
     1/20   7:05pm  2:00  Discovered and corrected two logical errors; code now
                            passes eleven tests
     1/23  11:00am  1:35  Finished debugging; program passes all public tests
                    ----
                    7:55  TOTAL time spent

     I discussed my solution with: Peter Salovey, Ben Polak, Tamar Gendler,
     and Jonathan Holloway (and watched four episodes of The Simpsons).

     *A brief discussion of the major difficulties encountered*

but MUST contain

your estimate of the time required (made prior to writing any code),
the total time you actually spent on the assignment,
the names of all others (but not members of the teaching staff) with whom you discussed the assignment for more than 10 minutes, and
a brief discussion (100 words MINIMUM) of the major conceptual and coding difficulties that you encountered in developing and debugging the program (and there will always be some).

This log will generally be worth 5-10% of the total grade.

N.B. To facilitate analysis, the log file MUST be the only file submitted whose name contains the string "log" and the estimate / total MUST be on the only line in that file that contains the string "ESTIMATE" / "TOTAL".

The submit program can be invoked in eight different ways:
```
% /c/cs223/bin/submit 5  Makefile Cloud.c btree.c time.log
```
submits the named source files as your solution to Homework #5;
```
% /c/cs223/bin/check 5
```
lists the files that you submitted for Homework #4;
```
 % /c/cs223/bin/unsubmit 5  error.submit bogus.solution
```
deletes the named files that you submitted previously for Homework #5 (which is useful if you rename a file or accidentally submit the wrong one);
```
% /c/cs223/bin/makeit  5 Cloud
```
runs "make" on the files that you submitted previously for Homework #4;
```
% /c/cs223/bin/testit  5  Cloud
```
runs the public test script for Cloud using the files that you submitted previously for Homework #5; This might not be working. Use the testing instructions given above.
```
% /c/cs223/bin/protect  6  Cloud.c time.log
```
protects the named files that you submitted previously for Homework #6 (so they cannot be deleted accidentally);
```
% /c/cs223/bin/unprotect  7  util.c time.log
```
unprotects the named files that you submitted previously for Homework #7 (so they can be deleted); and
```
% /c/cs223/bin/retrieve  8  common.c time.log
```
and
```
% /c/cs223/bin/retrieve  8  -d"2017/01/21 20:00" util.c
```
retrieve copies of the named files that you submitted previously for Homework #8 (in case you accidentally delete your own copies). The day and hour are optional and request the latest submission prior to that time (see the -d flag under "man co" for how to specify times).

When assignments are style graded, EVERY source file found in the submit directory will be reviewed. Thus prudence suggests using unsubmit to remove a file from the directory when you change its name or it ceases to be part of your solution. See http://zoo.cs.yale.edu/classes/cs223/doc/Style

Prudence (and a 5-point penalty for code that does not make) suggests that you run makeit ("makeit 5 Cloud") after you have submitted the final version of your source files. Better yet, run testit ("testit 5 Cloud").

The function exit() allows your program to stop immediately, without having to terminate any surrounding loops or to return to main() from a function. (To use it you must #include the header file <stdlib.h>.)