added tree class and traversals using recursion

C++/Tree/traversals.cpp

@@ -0,0 +1,31 @@
+#include <iostream>
+#include "tree.h"
+
+using namespace std;
+
+class Traversals {
+    public:
+        void PreorderTraversal(Tree* root) {
+            if (root == nullptr) return; 
+
+            cout << root->data_ << " -> ";  
+            PreorderTraversal(root->left_);
+            PreorderTraversal(root->right_); 
+        }
+
+        void InorderTraversal(Tree* root) {
+            if (root == nullptr) return; 
+
+            InorderTraversal(root->left_);
+            cout << root->data_ << " -> ";  
+            InorderTraversal(root->right_); 
+        }
+
+        void PostorderTraversal(Tree* root) {
+            if (root == nullptr) return; 
+
+            PostorderTraversal(root->left_);
+            PostorderTraversal(root->right_); 
+            cout << root->data_ << " -> ";    
+        }
+};

C++/Tree/tree.h

@@ -0,0 +1,21 @@
+#ifndef TREE_H_
+#define TREE_H_
+
+class Tree {
+    private:
+        //define extra members or methods if required
+    public:
+        // data members:
+        int data_;
+        Tree* left_;
+        Tree* right_;
+
+        // constructor:
+        Tree(int value, Tree* left = nullptr, Tree* right = nullptr) {
+            this->data_ = value;
+            this->left_ = left;
+            this->right_ = right;
+        }
+};
+
+#endif