BINARY SEARCH TREE-PRE,MID,POST TRAVERSAL METHODS.

/*

TOPIC: BINARY SEARCH TREE-PRE,MID,POST TRAVERSAL METHODS.
DATE:6/9/2012
*/

import java.util.*;
import java.io.*;
class Nodetype
{
      int info;
      Nodetype next,right,left,father ;
     Nodetype ()
      { //"the default info value is 03"
            this(3);

      }

 Nodetype (int i)
      {
            info = i ;
            left= null;
            right=null;
            father=null;

      }
}
class Operations
{
  Nodetype maketree(int x)
  {
    Nodetype node=new Nodetype(x);
    return(node);
  }

  void setleft(Nodetype p,int x)
  {
   if(p==null)
       System.out.println("Invalid insertion");
   else
     if(p.left!=null)
       System.out.println("Invalid insertion");
     else
       p.left=maketree(x);    
  }

   void setright(Nodetype p,int x)
  {
   if(p==null)
       System.out.println("Invalid insertion");
   else
     if(p.right!=null)
        System.out.println("Invalid insertion");
     else
        p.right=maketree(x);
     
   }
 
 

  void intrav(Nodetype ptree)
  {
    if(ptree!=null)
    { System.out.println();
       intrav(ptree.left);
       System.out.println(ptree.info+" ");
       intrav(ptree.right);
    }
  }

  void pretrav(Nodetype ptree)
  {
    if(ptree!=null)
    { System.out.println();
       System.out.println(ptree.info+" ");
       pretrav(ptree.left);
       pretrav(ptree.right);
    }
  }

  void postrav(Nodetype ptree)
  {
    if(ptree!=null)
    { System.out.println();
       postrav(ptree.left);
       postrav(ptree.right);
       System.out.println(ptree.info+" ");
    }
  }

  void create() throws Exception
  {
    BufferedReader br = new BufferedReader ( new InputStreamReader(System.in));
Nodetype ptree,p,q;
    int n,number=0;
    System.out.println(" Enter no. of nodes:");
    n=Integer.parseInt(br.readLine());
    System.out.println("enter info for"+n+" nodes:");
    number=Integer.parseInt(br.readLine());
    ptree=maketree(number);
    for(int i=1;i<n;i++)
    {
      number=Integer.parseInt(br.readLine());
      p=q=ptree;
      while(q!=null && number!=p.info)
      {
        p=q;
        if(number<p.info)
         q=p.left;
        else
         q=p.right;
      }
     if(number==p.info)
       System.out.println(number+" is duplicate");
     else
       if(number<p.info)
        setleft(p,number);
       else
        setright(p,number);
    }
    System.out.println("Inorder traversal:");
    intrav(ptree);
    System.out.println("preorder traversal: ");
    pretrav(ptree);
    System.out.println("postorder traversal: ");
    postrav(ptree);
  }

}

class Demo
{

    public static void main(String args[])throws Exception
    {
      Operations op=new Operations();
      op.create();
     System.out.println("thank u coded by TG");
}

}
/*
OUTPUT:
java Demo
 Enter no. of nodes:
13
enter info for13 nodes:
8
3
1
5
6
7
11
9
10
14
12
13
15
Inorder traversal:
1 3 5 6 7 8 9 10 11 12 13 14 15
preorder traversal:
8 3 1 5 6 7 11 9 10 14 12 13 15
postorder traversal:
1 7 6 5 3 10 9 13 12 15 14 11 8
thank u coded by TG
*/