TreeNode.java Source code

Introduction

Here is the source code for TreeNode.java

Source

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class TreeNode {
    TreeNode left, right;
    int data;

    TreeNode() {
        data = 0;
        left = right = null;
    }

    TreeNode(int n) {
        data = n;
        left = right = null;
    }

    void disp() {
        System.out.println(data + " ");
    }

    void setLeft(TreeNode n) {
        left = n;
    }

    void setRight(TreeNode n) {
        right = n;
    }

    TreeNode getLeft() {
        return left;
    }

    TreeNode getRight() {
        return right;
    }

    void setData(int d) {
        data = d;
    }

    int getData() {
        return data;
    }
}

class BinaryTree {
    TreeNode root;

    BinaryTree() {
        root = null;
    }

    void insert(int data) {
        root = insert(root, data);
    }

    TreeNode insert(TreeNode node, int data) {
        if (node == null) {
            node = new TreeNode(data);
        } else {
            if (data <= node.data) {
                node.left = insert(node.left, data);
            } else {
                node.right = insert(node.right, data);
            }
        }
        return (node);
    }

    void inorder() {
        inorder(root);
        System.out.println();
    }

    void inorder(TreeNode r) {
        if (r != null) {
            inorder(r.getLeft());
            System.out.print(r.getData() + " ");
            inorder(r.getRight());
        }
    }

    void preorder() {
        preorder(root);
        System.out.println();
    }

    void preorder(TreeNode r) {
        if (r != null) {
            System.out.print(r.getData() + " ");
            preorder(r.getLeft());
            preorder(r.getRight());
        }
    }

    void postorder() {
        postorder(root);
        System.out.println();
    }

    void postorder(TreeNode r) {
        if (r != null) {
            postorder(r.getLeft());
            postorder(r.getRight());
            System.out.print(r.getData() + " ");
        }
    }
}

public class Main {

    public static void main(String[] argv) throws IOException {
        BinaryTree bt = new BinaryTree();
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int val;
        char ch = ' ';
        String clearbuffer;
        do {
            System.out.print("Enter a number: ");
            val = Integer.parseInt(br.readLine());
            bt.insert(val);
            System.out.print("Do you wish to enter more values (Y/N).....");
            ch = (char) br.read();
            clearbuffer = br.readLine();
        } while (ch == 'y' || ch == 'Y');
        System.out.println("Postorder traversal of given tree is: ");
        bt.postorder();
        System.out.println("Preorder traversal of given tree is: ");
        bt.preorder();
        System.out.println("Inorder traversal of given tree is: ");
        bt.inorder();
    }
}