Project 3 -Questions:

CMSC341 --Fall 2001 -- Project 3

Kyu Bae xxx-xx-5868
section 201
kyu_bae@yahoo.com / kbae1@umbc.edu 

(1) Briefly describe how you would change your system to allow for multiple
    files to be loaded so that queries could run against more than one file
    at a time.  After all, a search engine that works for a single web page
    isn't all that useful.

 answer:

   I would change the command file so that "LOAD filename" can load several
   filenames at once. Like this, "LOAD filename1 filename2 filename3
   filename4" Then i will use getline() and use strtok to read in 
   each file name. After i read in
   one filename i build Binary Search TREE. Then i read in next filename
   and insert into the very same BSTree. and you continue untill you 
   read in all the filenames. The important thing to remember is that you
   don't call the destructor to make the tree empty or call makeEmpty()
   each time you read in filename and insert them into the tree.
   If you call the destructor or makeEmpty() each time you read
   in the file and inserting into the  tree. Basically you are
   making a new tree each time you read in  the filename. You
   want to read in all the filenames and insert  them into 
   one tree. In my program i called makeEmpty() beginning of "LOAD" 
   function. Before i read in the filename, i call makeEmpty() to 
   clean up the BS tree.. I am emptying the tree each time i load 
   new filename. So one of changes is that before i read in several 
   filenames i call the makeEmpty() to empty the previoud tree.
   and i do inserting into the tree...no destrucotr or makeEmpty() will
   be called a while i do those..Next time Load in is called then the 
   old tree will be cleaned.. 
   
       
(2) We required that members used as keys in a binary search tree be
    declared const.  Why?  What if all of the variants of find() returned a
    constant reference as they were originally defined in the book?  How
    would you have to change your code?

answer:
   The members used as keys in a binary search tree was declared 
   const in the textbook. Because all the find(), findMin(), and 
   findMax() return const reference. Which means you cannot find the
   node and change the data members of your node class.
   All the variants of find were const so you wanted  your data
   members of data class to be const also. You don't want users 
   to mess with the node of your binary search tree and change
   the contents of your data members.
   If all of the variants of find() were returned  a const 
   reference as they were originally defined in the book, then
   i have to change my data members of data class to be const.
   So they cannot be changed. Since all the variants of find()
   are returned as const references, i need to find a way to change 
   the contents of data members. This has to be done by Creating 
   a new Node(new object of Data class) and inserting this node instead
   of found node(instread of changing old node) after deleting the
   found node(old node). But before you delete and insert
   new node into tree. you must get the content of old node and add them
   into the new node. When you add old node into the new node , you
   add old node content and plus 1(increment the counter by one).
   Since you cannot change you old node's content, you need to copy
   old node into the new node after incrementing the count by one.
   and destroy old node and insert new one.
   
   My program did not delete old node. If found the node you are 
   trying to insert, i  called the addOneMore() of found node
   which just increment the  count data member by one and didn't 
   insert the newNode. If not found the  node you are trying to
   insert, insert it.