Added project readme

Author: hoangsonww

.idea/.gitignore

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

.idea/misc.xml

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+# Binary Search Tree Implementation
+
+## Overview
+This Java project implements a Binary Search Tree (BST) with fundamental operations such as insertion, deletion, and traversal. Designed with efficiency and simplicity in mind, this class provides an intuitive way to manage and manipulate a collection of integers in a hierarchical structure.
+
+## Features
+- **Dynamic Tree Construction**: Create a BST either empty, with a single root node, or by parsing an array of integers.
+- **Insertion**: Add new elements to the tree while maintaining the BST properties.
+- **Deletion**: Remove elements from the tree, adjusting the structure as necessary to preserve BST properties.
+- **Search**: Check whether a specific value exists within the tree.
+- **Traversal**: Inorder, preorder, and postorder traversal methods to explore the tree's contents.
+- **K-th Smallest Element**: Retrieve the k-th smallest element from the tree, demonstrating an application of inorder traversal.
+- **Create Tree from Array**: Build a new BST from an array of integers, replacing any existing tree.
+
+## Prerequisites
+- Java Development Kit (JDK) 11 or later.
+
+## Setup and Compilation
+1. Ensure Java is installed on your system. You can verify this by running `java -version` in your command line or terminal.
+2. Clone or download this repository to your local machine.
+3. Navigate to the directory containing the `BinarySearchTree.java` file.
+4. Compile the class using the Java compiler:
+   ```bash
+   javac BinarySearchTree.java
+   ```
+
+## Usage
+### Creating a BST
+Instantiate a BST object in your Java program. You can create a tree in three ways:
+- Empty tree: `BinarySearchTree bst = new BinarySearchTree();`
+- Tree with an integer root: `BinarySearchTree bst = new BinarySearchTree(10);`
+- Tree with a Node as root: `BinarySearchTree bst = new BinarySearchTree(new Node(10));`
+
+### Inserting Elements
+Add elements to your BST:
+```java
+bst.insert(5);
+bst.insert(15);
+```
+
+### Deleting Elements
+Remove elements by value:
+```java
+bst.delete(5);
+```
+
+### Searching for Elements
+Check if an element exists in the tree:
+```java
+boolean found = bst.search(15);
+```
+
+### Traversing the Tree
+Perform different tree traversals:
+```java
+bst.inorderRec();
+bst.preorderRec();
+bst.postorderRec();
+```
+
+### Finding the K-th Smallest Element
+Retrieve the k-th smallest element from the BST:
+```java
+Node kthSmallest = bst.kthSmallest(3);
+if (kthSmallest != null) {
+    System.out.println("K-th Smallest: " + kthSmallest.key);
+}
+```
+
+### Creating a Tree from an Array
+Overwrite the current tree with a new tree constructed from an array of integers:
+```java
+int[] values = {3, 1, 4, 2};
+bst.createTree(values);
+```
+
+## Contributing
+Contributions to improve the Binary Search Tree implementation or extend its functionality are welcome. Please fork the repository, make your changes, and submit a pull request with a clear description of your modifications or additions.
+
+## License
+Specify your project's license here, if applicable.
+
+---

.idea/modules.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
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+    <exclude-output />
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+    <orderEntry type="sourceFolder" forTests="false" />
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