Jan 30 2012 Lab Questions

What is hash?
How hash map works?
Different from other col, containers, data structures?
Complexity

http://www.cplusplus.com/reference/stl/
http://stackoverflow.com/questions/40471/differences-between-hashmap-and-hashtable
http://en.wikipedia.org/wiki/Hash_function


Array
Array List
Linked List
Tree Map
Hash Map
Dictionary

(access, insert, delete, space, next)


Speaking of Complexity - Check out this AWESOME PDF OF COMPLEXITY ANALYSIS WIN

SVN Repository 2.0 Spike

Instructions found HERE

Copy and paste is messy, so check out the text file HERE
       (Note - forgot a message on my first attempt importing a directory.)

Resources:
   how to clear history

Take Three - Java IO and Sorting

EDIT- 
Jan 21, 2012 
It was brought to my attention that there are libraries to implement different sorting algorithms.
I've decided NOT to reinvent the wheel (though I do intend to learn wheel-crafting in case I am ever in a jam).

C++ version of assignment :

• HERE 
• Tested with THIS text file
• OUTPUT
• Can sort by word count or alphabetical order  

NOTE:
Works on my machine, but compiling on trucks/moons doesn't work (doesn't recognize 'strtok' - scope issue? Perhaps there is an alternative? )


Main Resources :
fstream
STL Containers
STL Algorithms
Readtextfile
strtok
stringstream
convert-int-to-string

Looked At (Not so much used)
functors-and-their-uses
Bloom_filter
EmacsCheatSheet



TAKE THREE DRAFT:
So far, Version 3 on its way... Plus a few thoughts:

• realized I forgot to print a file with the other versions. (Fixed it)
• What's better?
• sorting as you add data 
• sorting after you've added all data
• What about functors? 
• make different functors for different algorithms?
• switch functors and compare times? 

How can I add color.... hmmm.....

Resources :
http://en.wikipedia.org/wiki/Function_object
http://www.roseindia.net/java/beginners/java-write-to-file.shtml
http://en.wikipedia.org/wiki/Merge_sort

Looked At (not so much used)
http://en.wikipedia.org/wiki/First-class_function
http://docs.oracle.com/javase/tutorial/java/javaOO/innerclasses.html
http://docs.oracle.com/javase/6/docs/api/java/util/Comparator.html
http://docs.oracle.com/javase/tutorial/java/javaOO/innerclasses.html

Take Two - Java File Reading

I got the bare basics working (see SVN ) but wanted to try storing words for later...

Version 2.0 <-CLK IT:

• gives Total word count
• gives unique word count
• stores words in hashtable --(currently re-evaluating this decision... not sold)

Main Differences:

• It runs.
• Imported only required header files
• Stores words in Hashtable if unique

Primary In-Class Difficulties :

• Lack of Java programming experience
• Main Issue = how to compile and run???
• javac FILENAME.java
• java FILENAME          //NO '.java' HERE!!!!!!
• Unfamiliar with Classes/Data structures/Variables/ Java Quirks
• Examples:
• must include Boolean (not a given like in c++)
• .java file needs to be a class, not just have main

Later Difficulties :

Nouns and Verbs - Data structures and Algorithms

•  How to store the data?
• I want to find the most commonly used words - I want a hierarchy, not just a single string-value pair (<-boring)
• Considered Hash tables
• How do I index or access in any order when my keys are non-numeric? Enum, but...eh. Shouldn't it be simpler?
• Considering Vector of String-Int pairs
• Could methodically insert
• How to sort the data?
• Algorithms
• Heap sort? Merge sort? Some....Sort? 
• n log(n)  for heap/merge

Version Three : The SORT-o-MATIC - coming soon to a blog near you.


References:
http://docs.oracle.com/javase/1.4.2/docs/api/java/util/Hashtable.html
http://www.java-samples.com/showtutorial.php?tutorialid=375 --not as helpful as I thought
http://en.wikipedia.org/wiki/Sorting_algorithm --WAAY too much I don't know here. Wow.
http://today.java.net/pub/a/today/2006/11/07/nuances-of-java-5-for-each-loop.html -- not working as expected
http://stackoverflow.com/questions/968347/can-a-java-file-have-more-than-one-class
http://stackoverflow.com/questions/513832/how-do-i-compare-strings-in-java
http://docs.oracle.com/javase/1.4.2/docs/api/java/util/Vector.html

ezSVN - Tired of Typing

• CURRENT WORRY ITEM #1: 
• CS svn appeared to be 'broken' for ~5 minutes this afternoon. (FREAKOUT)
• SOLUTION FOR WORRY #1:
• Back up for my back up:  Project Locker account 
• username smgonzal@unm.edu, (pw = left l-based)
• URL: https://pl5.projectlocker.com/smgonzal/Academic/svn

• CURRENT WORRY ITEM #2: 
• Tired of typing "svn checkout yadayadayada...." and can never remember the full path.
• SOLUTION FOR WORRY #2:
• svnget.sh - checks out specified svn repository
• possible arguments include ece, rc, cs, domegl, and pl 
• next step GUI??? Perhaps???

• CURRENT WORRY ITEM #3: 
• Couldn't remember how to svn something without checking out entire repository first...
• SOLUTION FOR WORRY #3:
• svnadd.sh - imports specified file to specified repository WITHOUT checking out first
• svnadd.sh [FILE_TO_IMPORT] [REPOSITORY_ABBREV]
• possible svn arguments include : ece, rc, cs, pl

Resources: 


Bash Guides (for those of us too lazy to commit this stuff to memory)
http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_07_01.html
http://www.linuxtutorialblog.com/post/tutorial-conditions-in-bash-scripting-if-statements

People
DJMK
SMG : http://cs.unm.edu/~smgonzal/svnHowTo.txt

File IO ....in Java (!)

  GNU nano 2.2.6                    File: fileIO.java                                            

//all io stuff we need
import java.io.*;

public class fileIO{
public static void main(String[] args){

    //What file will we read?
//    File myFile = new File("./textFile.txt");

    //create a filereader
    FileReader fr = new FileReader("/nfs/student/s/smgonzal/textFile.txt");
   
   //create buffered reader
    BufferedReader br = new BufferedReader(fr);

   int numWords = 0;

   //make string tokenizer
   StringTokenizer st;

//pseudo code...
//      while (not at end of file)
//      {
//        buffered reader gets next line
//        give it to tokenizer
//
//        //what if .,! etc are tokens though... this would be inacccurate
//        numWords = numWords + st.countTokens();
//      }

    System.out.println("number of Words: " + numWords);
}
};


Resources Used:

http://docs.oracle.com/javase/1.4.2/docs/api/java/io/BufferedReader.html
http://docs.oracle.com/javase/1.4.2/docs/api/java/io/File.html#File(java.lang.String)
http://docs.oracle.com/javase/1.4.2/docs/api/java/io/FileReader.html
http://www.abbeyworkshop.com/howto/java/readFile/index.html
http://docs.oracle.com/javase/1.4.2/docs/api/java/util/StringTokenizer.html

looked at (not so much used):
http://www.roseindia.net/java/beginners/java-word-count.shtml
http://stackoverflow.com/questions/5748656/unreported-exception-java-io-filenotfoundexception-must-be-caught-or-declared-t

Maybe...?

Just in case I do end up in CS351... Welcome to my blog.