Added BST template & standards

Author: amrithm98

CONTRIBUTING.MD

@@ -0,0 +1 @@
+Added a BST template.cpp for understanding c++11 and coding so that the code becomes readable.

template_bst.cpp

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+#include <bits/stdc++.h>
+using namespace std;
+ 
+template <typename T>
+class BinaryTreeNode {
+public:
+    T data;
+    BinaryTreeNode<T> *left;
+    BinaryTreeNode<T> *right;
+    
+    BinaryTreeNode(T data) {
+        this->data = data;
+        this->left = NULL;
+        this->right = NULL;
+    }
+};
+
+class BST
+{
+    BinaryTreeNode<int> *root;
+    
+    private:
+
+    BinaryTreeNode<int> *insert(BinaryTreeNode<int> *node,int data)
+    {
+        if(node == NULL)
+        {
+            node = new BinaryTreeNode<int>(data);
+            return node;
+        }
+        if(node->data < data)
+        {
+            node->right = insert(node->right,data);
+        }
+        else if(node->data > data)
+        {
+            node->left = insert(node->left,data);
+        }
+        return node;
+    }
+
+    BinaryTreeNode<int> *deleteData(BinaryTreeNode<int> *node,int data)
+    {
+        if(node == NULL)
+        {
+            return NULL;
+        }
+        if(node->data == data)
+        {
+            if(node->left == NULL && node->right == NULL)
+            {
+                free(node);
+                return NULL;
+            }
+
+            else if(node->left == NULL && node->right != NULL)
+            {
+                BinaryTreeNode<int> *nextNode = node->right;
+                free(node);
+                return nextNode;
+            }
+
+            else if(node->left != NULL && node->right == NULL)
+            {
+                BinaryTreeNode<int> *nextNode = node->left;
+                free(node);
+                return nextNode;
+            }
+
+            else if(node->left != NULL && node->right != NULL)
+            {
+                BinaryTreeNode<int> * inOrdSuc = node->right;
+
+                while(inOrdSuc->left != NULL)
+                    inOrdSuc = inOrdSuc->left;
+
+                node->data = inOrdSuc->data;
+                node->right = deleteData(node->right,inOrdSuc->data);
+                
+                return node;
+            }
+        }
+
+        if(node->data < data)
+            node->right = deleteData(node->right,data);
+
+        else if(node->data > data)
+            node->left = deleteData(node->left,data);
+
+        return node;
+        
+    }
+
+    bool hasData(int data,BinaryTreeNode<int> *root)
+    {
+        if(root == NULL)
+            return false;
+
+        if(root->data == data)
+            return true;
+
+        if(root->data < data)
+        {
+            return hasData(data,root->right);
+        }
+        else if(root->data > data)
+        {
+            return hasData(data,root->left);
+        }
+    }
+
+    void printTree(BinaryTreeNode<int> *node)
+    {
+        if(node == NULL)
+            return;
+
+        cout << node->data << ":";
+
+        if(node->left != NULL)
+            cout << "L:" << node->left->data << ",";
+
+        if(node->right != NULL)
+            cout << "R:" << node->right->data;
+        cout << endl;
+
+        printTree(node->left);
+        printTree(node->right);
+    }
+
+    public:
+
+    BST()
+    {
+        root = NULL;
+    }
+
+    void insert(int data)
+    {
+        root = insert(root,data);
+    }
+
+    void deleteData(int data)
+    {
+        root = deleteData(root,data);
+    }
+
+    bool hasData(int data)
+    {
+        return hasData(data,root);
+    }
+
+    void printTree()
+    {
+        printTree(root);
+    }
+    
+};
+
+int main()
+{
+    BST *tree = new BST();
+    int choice, input;
+    while(true){
+        cin>>choice;
+        switch(choice){
+            case 1:
+                cin >> input;
+                tree->insert(input);
+                break;
+            case 2:
+                cin >> input;
+                tree->deleteData(input);
+                break;
+            case 3:
+                cin >> input;
+                if(tree->hasData(input)) {
+                    cout << "true" << endl;
+                }
+                else {
+                    cout << "false" << endl;
+                }
+                break;
+            default:
+                tree->printTree();
+                break;
+        }
+    }
+    return 0;
+
+}