# What Is Binomial Heap in Data Structure?

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Larry Thompson

A binomial heap is a specialized tree-based data structure that is used to efficiently perform various operations such as insertion, deletion, and merging of elements. It was introduced by Jean Vuillemin in 1978. Binomial heaps are an extension of binary heaps and provide better time complexities for certain operations.

## Structure of a Binomial Heap

A binomial heap is made up of a collection of binomial trees, which are defined recursively as follows:

• A binomial tree of order 0 consists of a single node.
• A binomial tree of order k (where k > 0) is formed by taking two binomial trees of order k-1 and making one the leftmost child of the other. The root node of the tree with the larger key becomes the parent, while the other root node becomes its leftmost child.

Each binomial tree in a binomial heap satisfies the heap property – the key value of any node is greater than or equal to the key values of its children. Additionally, there can be at most one binomial tree for each order.

## Operations on Binomial Heaps

Binomial heaps support various operations that make them efficient for certain tasks:

### 1. Insertion

To insert an element into a binomial heap, we first create a new heap containing only the element. We then merge this new heap with the existing binomial heap by linking together trees with equal orders until there are no more trees with equal orders left. This process ensures that the resulting heap maintains the heap property.

### 2. Deletion

In a binomial heap, deleting an element involves two steps: first, we decrease its key to the minimum value, and second, we extract the minimum element from the heap. To decrease the key of an element, we swap its value with its parent until the heap property is satisfied.

After that, we extract the minimum element by finding the tree with the smallest root node and removing it from the heap. We then merge the children of this tree into a new binomial heap and merge it with the remaining trees.

### 3. Merging

The merging operation in binomial heaps involves combining two binomial heaps into a single heap. This is done by linking together trees with equal orders until there are no more trees with equal orders left in either of the heaps.

## Time Complexity Analysis

The time complexity of various operations on binomial heaps can be analyzed as follows:

• Insertion: O(log n)
• Deletion: O(log n)
• Merging: O(log n)

The logarithmic time complexities are achieved due to the unique properties of binomial trees and their efficient merging process.

## Applications of Binomial Heaps

Binomial heaps find applications in various domains, including:

• Priority queues: Binomial heaps can be used to implement priority queues efficiently, where elements are assigned priorities and processed accordingly.
• Graph algorithms: Binomial heaps are used in graph algorithms like Dijkstra’s algorithm and Prim’s algorithm for finding shortest paths and minimum spanning trees, respectively.
• Merge sort: Binomial heaps can be utilized as an alternative data structure for performing merge sort efficiently.

In conclusion, a binomial heap is a versatile data structure that offers efficient operations like insertion, deletion, and merging. Its unique properties and time complexities make it suitable for various applications in computer science.