# Double Tree with examples in C++ Program

C++Server Side ProgrammingProgramming

In this tutorial, we are going to learn how to double the given tree.

Let's see the steps to solve the problem.

• Create node class.

• Initialize the tree with dummy data.

• Write a recursive function to double the tree.

• Recursively traverse through the tree.

• Store the left node in a variable.

• After traversing add the data by creating a new node.

• Now, add the left node to the newly created node as a left child.

• Print the tree.

## Example

Let's see the code.

Live Demo

#include <bits/stdc++.h>
using namespace std;
class node {
public:
int data;
node* left;
node* right;
};
node* newNode(int data) {
node* Node = new node();
Node->data = data;
Node->left = NULL;
Node->right = NULL;
return Node;
}
void doubleTree(node* Node) {
node* oldLeft;
if (Node == NULL) return;
doubleTree(Node->left);
doubleTree(Node->right);
oldLeft = Node->left;
Node->left = newNode(Node->data);
Node->left->left = oldLeft;
}
void printTree(node* node) {
if (node == NULL) {
return;
}
printTree(node->left);
cout << node->data << " ";
printTree(node->right);
}
int main() {
node *root = newNode(1);
root->left = newNode(2);
root->right = newNode(3);
cout << "Original Tree" << endl;
printTree(root);
cout << endl;
doubleTree(root);
cout << "Double Tree" << endl;
printTree(root);
cout << endl;
return 0;
}

## Output

If you run the above code, then you will get the following result.

Original Tree
2 1 3
Double Tree
2 2 1 1 3 3

## Conclusion

If you have any queries in the tutorial, mention them in the comment section.