Extended binary tree is a type of binary tree in which all the null sub tree of the original tree are replaced with special nodes called external nodes whereas other nodes are called internal nodes
Here the circles represent the internal nodes and the boxes represent the external nodes.
Properties of External binary tree
- The nodes from the original tree are internal nodes and the special nodes are external nodes.
- All external nodes are leaf nodes and the internal nodes are non-leaf nodes.
- Every internal node has exactly two children and every external node is a leaf. It displays the result which is a complete binary tree
Below is an example of making an extended binary tree in C++ by making all the external nodes as ‘-1’
-1 5 -1 2 -1 1 -1 3 -1 4 -1
Application of extended binary tree:
- Calculate weighted path length: It is used to calculate total path length in case of weighted tree.
Here, the sum of total weights is already calculated and stored in the external nodes and thus makes it very easier to calculate the total path length of a tree with given weights. The same technique can be used to update routing tables in a network.
- To convert binary tree in Complete binary tree: The above-given tree having removed all the external nodes, is not a complete binary tree. To introduce any tree as complete tree, external nodes are added onto it. Heap is a great example of a complete binary tree and thus each binary tree can be expressed as heap if external nodes are added to it.
- Complexity of different operations in Binary tree, Binary Search Tree and AVL tree
- Minimum swap required to convert binary tree to binary search tree
- Check whether a binary tree is a full binary tree or not | Iterative Approach
- Convert a Binary Tree to Threaded binary tree | Set 2 (Efficient)
- Convert a Binary Tree to Threaded binary tree | Set 1 (Using Queue)
- Check whether a given binary tree is skewed binary tree or not?
- Check whether a binary tree is a full binary tree or not
- Check if a binary tree is subtree of another binary tree | Set 2
- Binary Tree to Binary Search Tree Conversion
- Binary Tree to Binary Search Tree Conversion using STL set
- Check if a binary tree is subtree of another binary tree | Set 1
- Difference between Binary Tree and Binary Search Tree
- Convert an arbitrary Binary Tree to a tree that holds Children Sum Property
- Print Binary Tree levels in sorted order | Set 3 (Tree given as array)
- Given level order traversal of a Binary Tree, check if the Tree is a Min-Heap
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