Given a Binary Tree, convert it to a Binary Search Tree. The conversion must be done in such a way that keeps the original structure of Binary Tree.
This solution will use Sets of C++ STL instead of array based solution.
Example 1 Input: 10 / \ 2 7 / \ 8 4 Output: 8 / \ 4 10 / \ 2 7 Example 2 Input: 10 / \ 30 15 / \ 20 5 Output: 15 / \ 10 20 / \ 5 30
- Copy the items of binary tree in a set while doing inorder traversal. This takes O(n log n) time. Note that set in C++ STL is implemented using a Self Balancing Binary Search Tree like Red Black Tree, AVL Tree, etc
- There is no need to sort the set as sets in C++ are implemented using Self-balancing binary search trees due to which each operation such as insertion, searching, deletion etc takes O(log n) time.
- Now simply copy the items of set one by one from beginning to the tree while doing inorder traversal of tree. Care should be taken as when copying each item of set from its beginning, we first copy it to the tree while doing inorder traversal, then remove it from the set as well.
Now the above solution is simpler and easier to implement than the array based conversion of Binary tree to Binary search tree explained here- Conversion of Binary Tree to Binary Search tree (Set-1), where we had to separately make a function to sort the items of the array after copying the items from tree to it.
Program to convert a binary tree to binary search tree using set.
Inorder traversal of BST is: 1 5 6 7 9 10 11
Time Complexity: O(n Log n)
Auxiliary Space: (n)
- Binary Tree to Binary Search Tree Conversion
- Minimum swap required to convert binary tree to binary search tree
- Complexity of different operations in Binary tree, Binary Search Tree and AVL tree
- Difference between Binary Tree and Binary Search Tree
- Count the Number of Binary Search Trees present in a Binary Tree
- Check whether a binary tree is a full binary tree or not | Iterative Approach
- Make Binary Search Tree
- Binary Search Tree | Set 2 (Delete)
- Iterative Search for a key 'x' in Binary Tree
- Floor in Binary Search Tree (BST)
- Search a node in Binary Tree
- Optimal Binary Search Tree | DP-24
- Sum of all the levels in a Binary Search Tree
- Binary Search Tree | Set 1 (Search and Insertion)
- Inorder Successor in Binary Search Tree
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.
Improved By : SHUBHAMSINGH10