Add Binary Search Implemetation

src/main/java/com/thealgorithms/tree/BinarySearchTree.java

@@ -0,0 +1,91 @@
+package com.thealgorithms.tree;
+
+public class BinarySearchTree {
+    class Node {
+        int key;
+        Node left,right;
+        Node(int key){
+            this.key = key;
+            left = right = null;
+        }
+
+    }
+
+    Node root;
+
+    public void insert(int key){
+        root = insertRec(root,key);
+    }
+
+    public Node insertRec(Node root, int key){
+        if(root == null){
+            return new Node(key);
+        }
+        if(key < root.key){
+            root.left = insertRec(root.left,key);
+        }else if (key > root.key){
+            root.right = insertRec(root.right,key);
+        }
+        return root;
+    }
+
+    public void inorder(){
+        inorderRec(root);
+    }
+
+    void inorderRec(Node root){
+        if(root != null){
+            inorderRec(root.left);
+            System.out.print(root.key + " ");
+            inorderRec(root.right);
+        }
+    }
+
+    public void preOrder(){
+        preOrderRec(root);
+    }
+
+    void preOrderRec(Node root){
+        if(root !=null){
+            System.out.print(root.key + " ");
+            preOrderRec(root.left);
+            preOrderRec(root.right);
+        }
+    }
+
+    public void postOrder(){
+        postOrderRec(root);
+    }
+
+    void postOrderRec(Node root){
+        if(root!=null){
+            postOrderRec(root.left);
+            postOrderRec(root.right);
+            System.out.print(root.key + " ");
+        }
+    }
+
+    public static void main(String[] args) {
+        BinarySearchTree tree = new BinarySearchTree();
+        // tree.insert(50);
+        // tree.insert(30);    
+        // tree.insert(20);
+        // tree.insert(40);
+        // tree.insert(70);
+        // tree.insert(60);
+        // tree.insert(80);
+
+        System.out.println("Inorder traversal of the given tree");
+        tree.inorder();
+        System.out.println();
+
+        System.out.println("Preorder traversal of the given tree");
+        tree.preOrder();
+        System.out.println();
+
+        System.out.println("Postorder traversal of the given tree");
+        tree.postOrder();
+        System.out.println();
+    }
+}
+