Double Tree with examples in C++ Program

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.

#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.

Hafeezul Kareem

Updated on: 28-Jan-2021

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