# What Is Full Binary Tree in Data Structure?

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Larry Thompson

A full binary tree is a type of binary tree where every node other than the leaves has two children. In other words, each internal node in a full binary tree has exactly two child nodes. Let’s dive deeper into understanding this concept and its significance in data structures.

## Properties of Full Binary Tree:

• Every node has either 0 or 2 children: In a full binary tree, each node can either have no children (i.e., it is a leaf node) or exactly two children.
• All leaves are at the same level: In a full binary tree, all the leaf nodes are present at the same level.
• The number of nodes at each level doubles: As we move from one level to the next in a full binary tree, the number of nodes doubles. For example, if the root level has 1 node, the next level will have 2 nodes, followed by 4 nodes, and so on.

## Examples of Full Binary Trees:

Let’s take a look at some examples to better understand what constitutes a full binary tree:

### Example 1:

A single node without any child is considered as a full binary tree because it satisfies all the properties mentioned above.

### Example 2:

A full binary tree with a root, a left child, and a right child. Both the left and right child are leaf nodes since they don’t have any further children attached to them.

```        O
/ \
O   O
```

### Example 3:

A full binary tree with a root and two internal nodes, each having two children. In this example, all the nodes except the leaf nodes have two children.

```        O
/ \
O   O
/ \ / \
O  OO  OO
```

## Applications of Full Binary Trees:

Full binary trees find their applications in various data structures and algorithms. Some of the use cases include:

• Heap Data Structure: Full binary trees are utilized in implementing heap data structures like binary heaps and priority queues.
• Binary Search Trees (BSTs): BSTs are a type of full binary tree that follow an ordering property.
• Huffman Coding Algorithm: Huffman coding algorithm uses full binary trees to compress data by assigning shorter codes to frequently occurring characters.

## In Conclusion:

A full binary tree is a special type of binary tree where every node (except leaves) has exactly two children. It exhibits certain properties like having either 0 or 2 children per node, all leaves at the same level, and a doubling number of nodes at each level. Understanding this concept is crucial when working with data structures and algorithms that leverage the properties of full binary trees.

Now that you have a clear understanding of what constitutes a full binary tree, you can confidently apply this knowledge to solve problems and design efficient algorithms.