A recursive approach to insert a new node in a BST is already discussed in the post: Binary Search Tree | SET 1. In this post, an iterative approach to insert a node in BST is discussed.
Insertion of a Key
A new key is always inserted at the leaf node. Start searching a key from root till we hit a leaf node. Once a leaf node is found, the new node is added as a child of the leaf node.
100 100 / \ Insert 40 / \ 20 500 ---------> 20 500 / \ / \ 10 30 10 30 \ 40
Approach: The idea is to note that new keys are always inserted at the leaf node.
- Take a temporary pointer named and start from the root node to traverse the tree downwards to find the correct leaf node at which the key is to be inserted.
- Also, keep track of the trailing pointer y to find the parent of the new node.
- After getting the final values of x and y, assign x as the left child of y if x->key is less than y->key. Else, if x->key is greater than y->key, assign x as the right child of y.(If the tree is NULL then the new node is made the root node.)
Below is the implementation of the above approach:
20 30 40 50 60 70 80
- Binary Search Tree insert with Parent Pointer
- Search a node in Binary Tree
- Find the node with maximum value in a Binary Search Tree
- Find the node with minimum value in a Binary Search Tree
- Postorder predecessor of a Node in Binary Search Tree
- Find the node with maximum value in a Binary Search Tree using recursion
- Find the node with minimum value in a Binary Search Tree using recursion
- Minimum swap required to convert binary tree to binary search tree
- Complexity of different operations in Binary tree, Binary Search Tree and AVL tree
- Binary Search Tree | Set 1 (Search and Insertion)
- Count the Number of Binary Search Trees present in a Binary Tree
- Binary Tree to Binary Search Tree Conversion using STL set
- Binary Tree to Binary Search Tree Conversion
- Difference between Binary Tree and Binary Search Tree
- Floor in Binary Search Tree (BST)
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