Remove operation on binary search tree is more complicated, than add and search. Basically, in can be divided into two stages: Remove algorithm in detail Now, let's see more detailed description of a remove algorithm. First stage is identical to algorithm for lookupexcept we should track the parent of the current node.

Second part is more tricky.

There are three cases, which are described below. This case is quite simple.

Algorithm sets corresponding link of the parent to NULL and disposes the node. It this case, node is cut from the tree and algorithm links single child with it's subtree directly to the parent of the removed node. This is the most complex case. To solve it, let us see one useful BST property first. We are going to use the idea, that the same set of values may be represented as different binary-search trees.

For example those BSTs:. To transform first tree into second one, we can do following:. Notice, that the node with minimum value has no left child and, therefore, it's removal may result in first or second cases only.

Find minimum element in the right subtree of the node to be removed. In current example it is Replace 12 with Notice, that only values are replaced, not nodes. Now we have two nodes with the same value.

First, check first if root exists. If not, tree is empty, and, therefore, value, that should be removed, doesn't exist in the tree. Then, check if delete a node in binary search tree c++ code value is the one to be removed. It's a special case and there are several approaches to solve it.

c# - Delete a node from a binary tree - Code Review Stack Exchange

We propose th e dummy ro ot method, when dummy root node is created and real root hanged to it as a left child. When remove is done, set root link to the link to the left child of the dummy root. In the languages without automatic garbage collection i.

For this needs, remove method in the BSTNode class should return not the boolean value, but the link to the disposed node and free the memory in BinarySearchTree class. BSTNode auxRoot 0.

Program to insert and delete a node from the binary search tree - C Programming Examples and Tutorials

Thanks for your apple stock option backdating scandal. We would appreciate a lot, if you point to the places in explanation, which delete a node in binary search tree c++ code hard to understand.

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c - Deleting a node from a Binary Tree Search - Stack Overflow

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Lookup operation on BST Next: Get values from BST in order. Contribute to AlgoList Liked this tutorial? Algorithms and Data Structures.

Binary Search Tree | Set 2 (Delete) - GeeksforGeeks

Removing a node Remove operation on binary search tree is more complicated, than add and search. Node to be removed has no children. Remove -4 from a BST. Node to be removed has one child. Remove 18 from a BST. Node to be removed has two children.

For example those BSTs: To transform first tree into second one, we can do following: The same approach can be utilized to remove a node, which has two children: Now, right subtree contains a duplicate!

Remove 12 from a BST. Remove 19 from the left subtree. Code snippets First, check first if root exists. Theory Aho, Ullman, Hopcroft.

Data Structures and Algorithms. Data Structures and Algorithms in Java. Practice Mark Allen Weiss. Lookup operation on BST.