[invincible_me]

hey friends

I am facing problem converting a code that reads a file with a number in different line eg
6
4
7
8
2

then building a tree(binary search tree) from this input file. the code i wrote is:

Code:

import java.util.*;
import java.io.*;
 
public class des {
 
  public static void main(String[] args)throws IOException
 
{
 
String s=null;
DataInputStream dis=new DataInputStream(System.in);
System.out.println("Enter the name of the file");
try
	{
		s = dis.readLine();
	}
catch(IOException e)
	{
	System.out.println("Nothing has been entered, please enter something");
	}
		//function(s);
 
 
 
new des().run(s);
  }
 
  static class Node {
    Node left;
 
    Node right;
 
    int value;
 
    public Node(int value) {
      this.value = value;
    }
  }
 
  public void run(String fn)throws IOException
 
{
   int q=-1,i=0;
int a[]=new int[100];
Node root=null;
FileReader fr;
	BufferedReader bf=null;
	String line,str=null;
	System.out.println("Filename is "+fn);
 
//	try
//		{
			fr=new FileReader(fn);
			bf=new BufferedReader(fr);
			while((line=bf.readLine()) !=null)
			{
 
			StringTokenizer st = new StringTokenizer(line);
												//while(st.hasMoreTokens())
				//{
				q++;
				try
				{
				str=st.nextToken();
				a[i]=Integer.parseInt(str);
				}
				catch(NumberFormatException e)
				{
				System.out.println(str+ " is not in the right format");
				System.out.println();
				q--;
				continue;
				}
 
				if(q==0)
				{
 
				 root = new Node(a[i]);
			System.out.println("Building tree with root value " + root.value);
				}
				if(i>0)
					insert(root,a[i]);
				i++;
			}
 
 
}
 
  public void insert(Node node, int value) {
    if (value < node.value) {
      if (node.left != null) {
        insert(node.left, value);
      } else {
        System.out.println("  Inserted " + value + " to left of "+ node.value);
        node.left = new Node(value);
      }
    } else if (value > node.value) {
      if (node.right != null) {
        insert(node.right, value);
      } else {
        System.out.println("  Inserted " + value + " to right of "+ node.value);
        node.right = new Node(value);
      }
    }
}
}

The problem is i want to convert this code to a code which takes as input a file like

6 6
4 6
3 6
2 4
1 4
2 3

where the first number in a line is a child and the second number is the parent of that child. the first line indicates that 6 is a root node.

kindly help me in changing the code above for this input.

thanks in anticipation