How to Read Binary Search Tree from File in C++?

A binary search tree is a hierarchical data structure in which for every node in the tree, the value of all nodes in the left subtree is less than the node's value and the value of all nodes in the right subtree is greater than the node's value. This property of the binary search tree makes it efficient for searching, insertion, and deletion operations. In this article, we will learn how to read files into a binary search tree using C++.

Read Data into a Binary Search Tree From a File

To create a binary search tree using the data present in a text file, we can follow the below approach:

Approach

1. Use ifstream to open the text file.
2. Check if the file is successfully opened. If not print an error message and exit the function.
3. Initialize an integer variable value to store the data from the file.
4. Use a loop to read integers from the file.
5. Inside the loop call the insert method to insert each integer into the Binary Search Tree.
6. Close the file after the creation of the Binary Search Tree is complete.

Note: In this program, we create the tree on the basis of key values that are integers. You can take any type of value as a key.

C++ Program to Read Binary Search Tree from File

Let us consider a text file named abc.txt that contains the following data 30 40 50 60 10 20.

Output

Inorder traversal of the constructed BST: 
10 20 30 40 50 60 
Level order traversal of the BST :
30 
10 40 
20 50 
60 
Search for 40 in the BST: Found

Time Complexity: O(NlogN) for constructing binary tree.
Auxiliary Space: O(N), where N is the number of nodes.