Create binarytree.java

binarytree.java

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+public class BinarySearchTree {    
+    //Represent the node of binary tree    
+    public static class Node{    
+        int data;    
+        Node left;    
+        Node right;    
+        public Node(int data){    
+            //Assign data to the new node, set left and right children to null    
+            this.data = data;    
+            this.left = null;    
+            this.right = null;    
+            }    
+        }    
+    //Represent the root of binary tree    
+    public Node root;    
+    public BinarySearchTree(){    
+        root = null;    
+    }    
+    //factorial() will calculate the factorial of given number    
+    public int factorial(int num) {    
+        int fact = 1;    
+        if(num == 0)    
+            return 1;    
+        else {    
+            while(num > 1) {    
+                fact = fact * num;    
+                num--;    
+            }    
+            return fact;    
+        }    
+    }    
+    //numOfBST() will calculate the total number of possible BST by calculating Catalan Number for given key    
+    public int numOfBST(int key) {    
+        int catalanNumber = factorial(2 * key)/(factorial(key + 1) * factorial(key));    
+        return catalanNumber;    
+    }    
+    public static void main(String[] args) {    
+        BinarySearchTree bt = new BinarySearchTree();    
+        //Display total number of possible binary search tree with key 5    
+        System.out.println("Total number of possible Binary Search Trees with given key: " + bt.numOfBST(5));    
+      }    
+}