Thread: Binary Tree insert(int value) method

So here is the code that I have. The problem is my insert method. It compiles, but it doesn't do so well in the test class I have set up for it.

package SystemandDesign.BinaryTree;
 
import java.io.FileInputStream;
import java.io.IOException;
import java.util.List;
import java.io.ObjectInputStream;
import java.util.Scanner;
 
public class BinaryTree{
 
  private int data;
  private List<Integer> list;
  private BinaryTree root;
  private BinaryTree leftSubtree;
  private BinaryTree rightSubtree;
  private ObjectInputStream input;
 
  public BinaryTree(int value){
 
    this.data = value;
    this.leftSubtree = null;
    this.rightSubtree = null;
    this.root = null;
 
  }
 
  public int getData(){
 
    return this.data;
 
  }
 
  public BinaryTree getRoot() {
    return this.root;
  }
 
  public void insert(int value){
 
    if(root == null){//starts a new Binary tree
      root = new BinaryTree(value);
    }
 
    else if(value < data){//if the data being inserted is less than the original data, it will be inserted to the left side.
 
      if(leftSubtree == null){
        leftSubtree = new BinaryTree(value);
      }
      else{
        leftSubtree.insert(value);
      }
 
    }
    else if(value > data){//right side of binary tree
 
      if(rightSubtree == null){
        rightSubtree = new BinaryTree(value);
      }
      else{
        rightSubtree.insert(value);
      }
 
    }
 
 
  }
 
  public void inOrder(BinaryTree leaf, List<Integer> list){
    System.out.println(leaf);
    if(leaf != null){
      inOrder(leaf.leftSubtree, list);
      //System.out.print(leaf.data+"");
      list.add(leaf.getData());
      inOrder(leaf.rightSubtree, list);//Have it return an arrayList. 
    }
    else {
 
    }
  }
 
  public static void main(String[] args){
    BinaryTree tree = new BinaryTree(9);
    tree.openFile();
    tree.readFile();
    tree.closeFile();
  }
 
  public void openFile(){
    try{
    input = new ObjectInputStream(new FileInputStream("C:\\Users\\Carlos Sotres\\Documents\\SystemandDesign\\data.ser"));
  }catch(IOException ioException){
    System.err.println("Error opening file.");
  }
  }
  public void readFile(){ 
  try{
    Scanner in = new Scanner(new FileInputStream("data.ser"));
  }catch(IOException e){
    System.err.println("Error class not found");
    System.err.println(e);
  }
  }
  public void closeFile(){
    try{
      if(input != null)
        input.close();
    }catch(IOException ioException){
      System.err.println("Error closing file.");
      System.exit(1);
    }
  }
}

Here is a look at my test class:

package SystemandDesign.BinaryTree;
 
import junit.framework.TestCase;
import java.util.List;
import java.util.ArrayList;
public class BinaryTreeTest extends TestCase{
 
  BinaryTree d1;
  BinaryTree d2;
  BinaryTree d3;
  BinaryTree d4;
  BinaryTree d5;
  BinaryTree d6;
  BinaryTree d7;
  BinaryTree d8;
 
 
  public void setUp(){
 
    d1 = new BinaryTree(2);
    d1.openFile();
    d2 = new BinaryTree(5);
    d3 = new BinaryTree(9);
    d4 = new BinaryTree(10);
    d5 = new BinaryTree(12);
    d6 = new BinaryTree(19);
    d7 = new BinaryTree(3);
    d8 = new BinaryTree(4);
  }
//  public void testInsert(){
//    assertEquals(d1,d3);
//    
//    
//  }
  public void testinOrder(){
    List<Integer> leaves = new ArrayList<Integer>();
    d1.insert(1);
    d1.insert(2);
    d1.insert(3);
    System.out.println(d1.getRoot());
    d1.inOrder(d1.getRoot(), leaves);
    System.out.println(leaves);
 
 
  }
  }

Here is a copy of the console:

Class edu.rice.cs.plt.lambda.SimpleBox@156c089added to classNames. File C:\Users\Carlos Satres\Documents\SystemandDesign\BinaryTree\Binary Tree.java added to files.
Class edu.rice.cs.plt.lambda.SimpleBox@1ce18cadded to classNames. File C:\Users\Carlos Satres\Documents\SystemandDesign\BinaryTree\Binary TreeTest.java added to files.
Error opening file.
SystemandDesign.BinaryTree.BinaryTree@b93ab6
SystemandDesign.BinaryTree.BinaryTree@b93ab6
null
null
[1]

Its supposed to walk the BinaryTree inOrder Traverse, and print out the array in that order, here is my modification to the insertMethod, it looks like it reads the root and and rightSubtree with the current test parameters

public void insert(int value){
 
    if(root == null){//starts a new Binary tree
      root = new BinaryTree(value);
      System.out.println("yes Root");
    }
 
    else if(value < data){//if the data being inserted is less than the original data, it will be inserted to the left side.
 
      if(leftSubtree == null){
        System.out.println("yes Left Subtree");
        leftSubtree = new BinaryTree(value);
      }
      else{
        leftSubtree.insert(value);
      }
 
    }
    else if(value > data){//right side of binary tree
 
      if(rightSubtree == null){
        System.out.println("yes Right Subtree");
        rightSubtree = new BinaryTree(value);
      }
      else{
        rightSubtree.insert(value);
      }
 
    }
 
 
  }

it doesn't do so well

Please explain.

What should the program's output look like?

The output that was posted is hard to read because it appears that the lines are run together. Can you separate the lines to make it easier to read?

Can you post a sample of what the output should look like for the data that current program has?

returns null for both left and right subtrees

Try debugging the code by adding some println() statements that print out the values of variables as they are changed so you can see what the computer sees as the code is executed.

Originally Posted by Norm

Can you post a sample of what the output should look like for the data that current program has?


Try debugging the code by adding some println() statements that print out the values of variables as they are changed so you can see what the computer sees as the code is executed.

Its supposed to walk the BinaryTree inOrder Traverse, and print out the array in that order, here is my modification to the insertMethod, it looks like it reads the root and and rightSubtree with the current test parameters:_______________________________________ _______________________

  public void insert(int value){
 
    if(root == null){//starts a new Binary tree
      root = new BinaryTree(value);
      System.out.println("yes Root");
    }
 
    else if(value < data){//if the data being inserted is less than the original data, it will be inserted to the left side.
 
      if(leftSubtree == null){
        System.out.println("yes Left Subtree");
        leftSubtree = new BinaryTree(value);
      }
      else{
        leftSubtree.insert(value);
      }
 
    }
    else if(value > data){//right side of binary tree
 
      if(rightSubtree == null){
        System.out.println("yes Right Subtree");
        rightSubtree = new BinaryTree(value);
      }
      else{
        rightSubtree.insert(value);
      }
 
    }
 
 
  }

Please edit your post and wrap your code with code tags:
[code=java]
YOUR CODE HERE
[/code]
to get highlighting and preserve formatting.

One hole in the code is the missing else statement at the end of the if/else if chain. There should be code there to catch missed conditions.

See the code in post#5