Question

Please help to this program:

Using Java programming language Create a binary tree class. Using the class, create a program that prompts the user for a text file. The program should parse the file, assigning each word the file contains to a node within the binary tree. Each node within the binary tree should store a word and keep a count of the number of times the word has occurred within the file. The program should output the words in alphabetical order along with their count.

Answer 1

BNode.java

//BNode class is user to create a node
class BNode
{
   BNode left,right;
   int count;
   String word;

   public BNode(String word)
   {
       this.word=word;
       this.count=1;
       this.left=null;
       this.right=null;
   }
}

BST.java

//BST class contains implementation of all required methods
class BST
{
   private BNode root;
   //Constructor
   public BST()
   {
       root=null;
   }
   //call insert by passing root
   public void insert(String word)
   {
       insert(root,word);
   }
   public void insert(BNode node, String word)
   {
       //If root is null then make it as root
       if(root==null)
       {
           root=new BNode(word);
       }
       //If current node value is lexiographically greater than word then go to left subtree
       else if(word.compareToIgnoreCase(node.word)<0)
       {
           //If left node is null then make it as left node
           if(node.left==null)
           {
               node.left=new BNode(word);
               return;
           }
           //Else go to left node
           insert(node.left,word);
       }
       //If current node value is lexiographically smaller than word then go to right subtree
       else if(word.compareToIgnoreCase(node.word)>0)
       {
           //If right node is null then make it as right node
           if(node.right==null)
           {
               node.right=new BNode(word);
               return;
           }
           //Else go to right node
           insert(node.right,word);
       }
       //If node already existed then increments it's occurance
       else
       {
           node.count++;
       }
   }
   public void inorder()
   {
       inorder(root);
   }
   //Inorder to print the tree in lexiographic order
   public void inorder(BNode node)
   {
       if(node!=null)
       {
           inorder(node.left);
           System.out.println(node.word+" "+node.count);
           inorder(node.right);
       }
   }
}

Demo.java

import java.util.Scanner;
import java.util.StringTokenizer;
import java.io.*;

class Demo
{
   public static void main(String args[])throws IOException
   {
       //Scanner class to take file name from user
       Scanner scanner=new Scanner(System.in);
       System.out.print("Enter file name: ");
       String file=scanner.next();

       //Open file
       FileReader fr=new FileReader(file);
       BufferedReader br=new BufferedReader(fr);
       //Create object for BST
       BST bst=new BST();
       String s="";
       //Get each line of file to string S
       while((s=br.readLine())!=null)
       {
           //Split string S into words
           StringTokenizer st=new StringTokenizer(s);
           //Iterate until there are no words in line
           while(st.hasMoreTokens())
           {
               //Insert each word
               bst.insert(st.nextToken());
           }
       }
      
       //Call inorder to print the output as lexiographic order
       bst.inorder();

       //close the file
       br.close();
       fr.close();
   }
}

output screenshot:

input.txt:

ant ball bingo cat dog ant cat goat
jeep ball zoo yet good boy you are
you are very good boy you are very good girl
i am david
i am doing job