Binary search tree in cpp

Contributors.md

@@ -38,3 +38,4 @@
 * ![Rashi Singh](https://github.com/RASHI3004)
 * ![Amrit Anwesh](https://github.com/shinozaki1595)
 * ![Vrutansh Patel](https://github.com/vrutansh)
+* ![neyaz-ahmad](https://github.com/neyaz-ahmad)

c++/Searching/binary search tree.cpp

@@ -0,0 +1,183 @@
+
+
+#include<iostream>
+using namespace std;
+
+class BinarySearchTree {
+
+    struct BSTnode {
+        int data;
+        BSTnode* left;
+        BSTnode* right;
+    };
+
+    BSTnode* root;
+
+    //Function to Clear a Node
+    BSTnode* clear(BSTnode* t) {
+        if(t == NULL)
+            return NULL;
+        {
+            clear(t->left);
+            clear(t->right);
+            delete t;
+        }
+        return NULL;
+    }
+
+    //Function to Insert a Node
+    BSTnode* insert(int x, BSTnode* t)
+    {
+        if(t == NULL)
+        {
+            t = new BSTnode;
+            t->data = x;
+            t->left = t->right = NULL;
+        }
+        else if(x < t->data)
+            t->left = insert(x, t->left);
+        else if(x > t->data)
+            t->right = insert(x, t->right);
+        return t;
+    }
+
+    //Function to Obtain the Node with the Minimum Value
+    BSTnode* min(BSTnode* t)
+    {
+        if(t == NULL)
+            return NULL;
+        else if(t->left == NULL)
+            return t;
+        else
+            return min(t->left);
+    }
+
+    //Function to Obtain the Node with the Maximum Value
+    BSTnode* max(BSTnode* t) {
+        if(t == NULL)
+            return NULL;
+        else if(t->right == NULL)
+            return t;
+        else
+            return max(t->right);
+    }
+
+    //Function to Delete/Remove a Node from the BST
+    BSTnode* remove(int x, BSTnode* t) {
+        BSTnode* temp;
+        if(t == NULL)
+            return NULL;
+        else if(x < t->data)
+            t->left = remove(x, t->left);
+        else if(x > t->data)
+            t->right = remove(x, t->right);
+        else if(t->left && t->right)
+        {
+            temp = min(t->right);
+            t->data = temp->data;
+            t->right = remove(t->data, t->right);
+        }
+        else
+        {
+            temp = t;
+            if(t->left == NULL)
+                t = t->right;
+            else if(t->right == NULL)
+                t = t->left;
+            delete temp;
+        }
+
+        return t;
+    }
+
+    //Function to Display Inorder Traversal of the BST
+    void inorder_traversal(BSTnode* t) {
+        if(t == NULL)
+            return;
+        inorder_traversal(t->left);
+        cout << t->data << " ";
+        inorder_traversal(t->right);
+    }
+
+    //Function to Search and Check whether a Given Node is Present in the BST or Not
+    BSTnode* search(BSTnode* t, int x) {
+        if(t == NULL)
+            return NULL;
+        else if(x < t->data)
+            return search(t->left, x);
+        else if(x > t->data)
+            return search(t->right, x);
+        else
+            return t;
+    }
+
+public:
+    //Creating Corresponding Functions for the Object to Acccess Outside the Class
+    BinarySearchTree() {
+        root = NULL;
+    }
+
+    ~BinarySearchTree() {
+        root = clear(root);
+    }
+
+    void insert(int x) {
+        root = insert(x, root);
+    }
+
+    void remove(int x) {
+        root = remove(x, root);
+    }
+
+    void display() {
+        inorder_traversal(root);
+        cout << endl;
+    }
+
+    void search(int x) {
+        root = search(root, x);
+        if(root == NULL)
+            cout << endl << x <<" is Not Present in the BST";
+        else
+            cout<< endl << x <<" is Present in the BST";
+    }
+};
+
+int main() {
+    //Creating Object of BinarySearchTree Class
+    BinarySearchTree t;
+
+    //Inserts the Following Nodes into the BST
+    t.insert(20);
+    t.insert(25);
+    t.insert(15);
+    t.insert(10);
+    t.insert(30);
+
+    //Displays Inorder Traversal of BST
+    t.display();
+
+    //Remove 20 and 25 From the BST and Display Corresponding Inorder Traversal
+    t.remove(20);
+    t.display();
+    t.remove(25);
+    t.display();
+
+    t.search(15);
+    return 0; 
+}
+
+//Output :
+//10 15 20 25 30                                                                                                          
+//10 15 25 30                                                                                                             
+//10 15 30                                                                                                                                                                                                                                      
+//15 is Present in the BST                                                                                                 
+//20 is Not Present in the BST
+
+//Time Complexity :
+//Insertion : O(h) [h = Height of BST]
+//Deletion : O(h) [h = Height of BST]
+//Searching : O(h) [h = Height of BST]
+
+//Space Complexity :
+//O(n) [n = Number of Nodes in BST]