coding difficulty
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:
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");
}
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);
fr=new FileReader(fn);
bf=new BufferedReader(fr);
while((line=bf.readLine()) !=null)
{
StringTokenizer st = new StringTokenizer(line);
q++;
try
{
str=st.nextToken();
a=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);
System.out.println("Building tree with root value " + root.value);
}
if(i>0)
insert(root,a);
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
