Count word frequency using Binary Search Tree

Here is the header file:

#ifndef BST_H
#define BST_H

typedef int elem;

class record {
public:
      record() {sentence = ("\0"); element = ("\0"); freq_count = 0;}
      //~record();
      int getSentence(int);
private:
      string sentence;
      string element;
      int freq_count;
};

class node {                     // Binary tree node class
public:
    elem element;                // The node's value
    node* left;                    // Pointer to left child
    node* right;                   // Pointer to right child

    node() { left = right = NULL; }
    node(elem tmp2, node* l = NULL, node* r = NULL)
      { element = tmp2; left = l; right = r; }
   ~node() { }                  // Destructor

    elem value() const { return element; };
    void setValue(elem val) { element = val; }
    node* leftchild() const { return left; }
    node* rightchild() const { return right; }
    bool isLeaf() const            // Return TRUE if is a leaf
        { return (left == NULL) && (right == NULL); }
};

class tree {
private:
    node* root;
    void clearStub(node*);       // Helper functions for public routines
    void insertStub(node*&, const elem);
    node*deletemin(node*&);
    void removeStub(node*&, int);
    elem findStub(node*, int) const;
    void printStub(const node*, int) const;
public:
    tree() { root = NULL; }
   ~tree() { clearStub(root); }
    void clear() { clearStub(root); root = NULL; }
    void insert(elem val) { insertStub(root, val); }
    void remove(const val) { removeStub(root, val); }
    elem find(const val) const { return findStub(root, val); }
    bool isEmpty() const { return root == NULL; }
    void print() const {
        if (root == NULL) cout << "The tree is empty.\n";
        else printStub(root, 0);
    }
};
#endif

####################################################################

And the Driver File:

#include <iostream>
#include <assert.h>
#include <fstream>
#include <string>

using namespace std;

#include "bst.h"

#define      SIZE      10

#define UNSUCCESSFUL -1
#define key(X) (int)(X)
#define visit(X) cout << rt->element << " ";

//Global Variables
string sentence;
int numberOfLines;

void tree::clearStub(node* rt) {// Clear all nodes from the tree
    if (rt == NULL) return;
    clearStub(rt->leftchild());
    clearStub(rt->rightchild());
    delete rt;
}

void tree::insertStub(node*& rt, const elem val) {
    if (rt == NULL)                  // Empty tree: create node
        rt = new node(val, NULL, NULL);
    else if (key(val) < key(rt->value()))
        insertStub(rt->left, val);     // Check left
    else insertStub(rt->right, val); // Check right
}

void tree::removeStub(node*& rt, int val) {
    if (rt == NULL) cout << val << " is not in the tree.\n";
    else if (val < key(rt->value()))       // Check left
        removeStub(rt->left, val);
    else if (val > key(rt->value()))       // Check right
        removeStub(rt->right, val);
    else {                                 // Found it: remove it
        node* temp = rt;
        if (rt->left == NULL)            // Only a right child
            rt = rt->right;                  // so point to right
        else if (rt->right == NULL)          // Only a left child
            rt = rt->left;                   // so point to left
        else {                               // Both children are non-empty
            temp = deletemin(rt->right);// Replace with min value
        rt->setValue(temp->value());       // in right subtree
        }
        delete temp;                   // Return node to free store
    }
}

node* tree::deletemin(node*& rt) {
    assert(rt != NULL);       // There must be a node to delete
    if (rt->left != NULL)     // Continue left
        return deletemin(rt->left);
    else                      // Found it
        { node* temp = rt; rt = rt->right; return temp; }
}

elem tree::findStub(node* rt, int val) const {
    if (rt == NULL) return UNSUCCESSFUL; // Empty tree: nothing found
    else if (val < key(rt->value()))             // Check left
        return findStub(rt->leftchild(), val);
    else if (val == key(rt->value())) return rt->value();
    else return findStub(rt->rightchild(), val); // Check right
}

// Print the nodes of a tree; use indentation to indicate tree shape
void tree::printStub(const node *rt, int level) const {
    if (rt == NULL) return;               // Empty tree
        printStub(rt->rightchild(), level+1);  // Print left subtree
    for (int i=0; i<level; i++)           // Indent to level
        cout << "    ";
    cout << rt->value() << "\n";          // Print node value
    printStub(rt->leftchild(), level+1); // Print right subtree
}

void preorder(node* rt)        // rt is the root of a subtree
{
    if (rt == NULL) return;         // Empty subtree
    visit(rt);              // visit performs whatever action is desired
    preorder(rt->leftchild());
    preorder(rt->rightchild());
}

int record::getSentence(int numberOfLines)
{
      numberOfLines = 0;
      int count = 1;
      char *tokenPtr;
      char string[SIZE][101];

      ifstream inFile1("testing.txt", ios::in);//This is the file I used, U may change it.

      if(!inFile1)
      {
            cerr<<"ERROR: File does not exist"<<endl;
            void main();
      }

      while(!inFile1.eof())
      {
            getline(inFile1, sentence);
            numberOfLines++;//Count number of lines
      }

      inFile1.close();

      ifstream inFile2("testing.txt", ios::in);//Change to the same name here as well..

      if(!inFile2)
      {
            cerr<<"ERROR: File does not exist"<<endl;
            void main();
      }

      while(numberOfLines>0)
      {
            cout<<"\n\nThis is line number: "<<count<<endl;
            inFile2.getline(string[numberOfLines], 100);
            tokenPtr = strtok(string[numberOfLines], " ,.?!");

            while (tokenPtr != NULL)
            {
                  cout<<tokenPtr<<endl;
                  tokenPtr = strtok(NULL, " ,.?!"); //Using delimiters " ,.?!" to seperate words
            }
            numberOfLines--;
            count++;
      }


      cout<<"Number of lines in the file are: "<<count - 1<<endl;

      return 0;
}

void main()
{
      char choice;
      record tmp;

      do{
            cout<<"\n\n(1) Load Text"<<endl;
            cout<<"(2) Display Sorted Words"<<endl;
            cout<<"(3) Exit"<<endl;

            cout<<"Please select an option: ";
            cin >>choice;

            switch(toupper(choice))
            {
            case 'L': tmp.getSentence(numberOfLines);
                  break;
            case 'D':
                  break;
            case 'E':
                  break;
            };
      }while(toupper(choice) != 'E');
      
}
//The code given below is what was used for testing the BST.
//You can use it too, just replace the whole main body with this stuff.
    /*tree t;
    cout << "insert 30\n"; t.insert(30);  
    cout << "insert 13\n"; t.insert(13);
    cout << "insert 50\n"; t.insert(50);
    cout << "insert 10\n"; t.insert(10);
    cout << "insert 20\n"; t.insert(20);
    cout << "insert 40\n"; t.insert(40);
    cout << "insert 70\n"; t.insert(70);
    cout << "insert 35\n"; t.insert(35);
    cout << "insert 90\n"; t.insert(90);
    t.print();
    cout << "remove 13\n"; t.remove(13);  
    t.print();
    cout << "remove 50\n"; t.remove(50);  
    t.print();
    t.clear();
    t.print();*/

########################################################
I am expecting the output something like this:
Word    Frequency    LineNum
and       5                 2, 4
for        3                  1, 3
what     2                  2,3



Note: It will be better if the words are displayed in alphabetical order.

Thanks,
Arjun

(1) What is your question?

(2) In InsertStub
  - Why is val passed by constant value? It would seem that constant reference would make more sense
  - Why are you using the key() macro? Or rather, why haven't you defined the key() macro to work with your data?
  - What _is_ the sorting order you expect to use in your BST? If your output should be sorted in word order, doesn't it make sense to use the words as the key for the BST?
 
(3) General question: If you're keeping count and line number information, isn't it possible for a word to appear on multiple lines? I am wondering what you will do in that case. Also, the code you show does not handle nodes with duplicate keys (that is, it always inserts a new node). You will want to make sure you know what happens the second time your code encounters "the" or "a" in the input (assuming English input file).

Good luck, -bcl

First of all thanks for such a fast response.

(1) My main question is how to write a BST program which stores the words and their frequency of appearence in the text file.
Like for example if u have a text file like this:
Peter brought some butter but the butter was bitter
so peter brought some better butter to make the
bitter butter better.

The program must give output like this:
Word     Frequency      Line Numbers
peter      2                   1, 2
brought  2                    1, 2
better     2                    2, 3
and so on...

(2) The code is my friends and I don't understand all of it... :\ But I guess the const does not make a difference anyway. You can remove it...
I am not entirely sure what the key macro does, but I guess its like comparing the values to see which tree to go to next rite? As in go to the left part or the right part of the tree and then insert the new node there.
By the sorting order you mean post, pre or inorder rite? Thats were I am not sure as well.. What I want is just to display in alphabetical order. So I think only inorder will work? Not sure there though.

(3) The file I have pasted here is the unmodified one. It uses val in the BST. val is just a int data type. What I have been trying is to completely remove the val thing and replace it with my class. So instead of storing integers in the node's data, I will have the class record which contains the word, its frequency and the line numbers in which it appears. And yah, the input file is in English. We can leave aside the duplicate nodes aside first. I can handle that.

Thanks once again,
Arjun

After reading your description and some other online descriptions of the key macro, I think i found my fault. Need to change my code and try though. But I am pretty sure it lies in the usage of the macro key. Yah anyway I don't ask home work questions here :) Haha.. you can check my previous questions :)

Thanks for the guidelines.. Will get back to you ASAP after i try it out agian.

Thanks yet again
Arjun

Yep finally I got it to work a few days back..
Thanks for helping!

Arjun