# What Is Min and Max Heap in Data Structure?

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Angela Bailey

A min heap and a max heap are two important data structures used in computer science and are specifically designed to efficiently support the operations of finding the minimum or maximum element in a dataset, respectively. These heaps are implemented as complete binary trees, where each node holds a value that is either greater or smaller than its child nodes. This article will explore the concepts of min and max heaps, their properties, and their applications in various algorithms.

## Heap Data Structure

A heap is a specialized tree-based data structure that satisfies the heap property. The heap property states that for any given node in the tree, the value of that node is either greater or smaller than the values of its child nodes, depending on whether it is a max heap or a min heap.

### Min Heap

In a min heap, for every node X, the value of X is smaller than or equal to the values of its child nodes. This means that the smallest element in the heap will always be at the root of the tree.

• A min heap can be visualized as an upside-down binary tree with each level filled from left to right.
• The root node contains the smallest element in the entire heap.
• All subtrees within a min heap also satisfy the min heap property.
• The height of a min heap can vary depending on the number of elements but always remains logarithmic with respect to its size.

### Max Heap

In contrast, a max heap follows similar rules but with reversed inequalities: for every node X, the value of X is greater than or equal to the values of its child nodes. This means that the largest element in the heap will always be at the root.

• A max heap can also be visualized as an upside-down binary tree with each level filled from left to right.
• The root node contains the largest element in the entire heap.
• All subtrees within a max heap also satisfy the max heap property.
• Similar to a min heap, the height of a max heap remains logarithmic with respect to its size.

## Applications of Min and Max Heaps

The min and max heaps find their applications in various algorithms and data structures due to their efficient operations:

• Priority Queues: Heaps are commonly used as the underlying data structure for implementing priority queues, where elements are assigned priorities and can be efficiently retrieved based on their priority levels.
• Heap Sort: The heapsort algorithm utilizes a max heap to sort elements in ascending order. By repeatedly extracting the maximum element from the max heap, we can construct a sorted list of elements.
• Kth Largest/Smallest Element: Using a min or max heap, we can efficiently find the kth largest or smallest element in an array or stream of data, without needing to sort it entirely.
• Dijkstra’s Algorithm: This popular shortest path algorithm utilizes a min heap as part of its implementation for efficiently selecting and processing vertices with minimum distances during traversal.

In conclusion, min and max heaps are powerful data structures that enable efficient retrieval of minimum and maximum elements, respectively. Understanding their properties and applications can greatly enhance your knowledge of data structures and algorithms, and enable you to design more efficient solutions to various problems.