**What Is Merge Sorting in Data Structure?**

Sorting is a fundamental operation in computer science, and there are various algorithms available to accomplish this task efficiently. One such algorithm is merge sort, which is widely used due to its efficiency and simplicity.

**How does merge sort work?**

Merge sort follows the divide-and-conquer strategy to sort an array or a list of elements. The algorithm involves recursively dividing the input into smaller subproblems, sorting them individually, and then merging them together to obtain the final sorted result.

## Divide and conquer

The first step in merge sort is to divide the input into two halves until each subproblem contains only one element. This process of dividing continues until we reach the base case, where a single element is considered sorted by default.

## Merging sorted subarrays

After dividing the input into smaller subproblems, we begin merging them back together. Merging involves comparing elements from each subarray and placing them in the correct order into a new array or list.

### The merging process:

- Compare the first elements from both subarrays.
- Place the smaller element into the new array.
- Move to the next element in the subarray from which we took the smaller element.
- Repeat steps 1-3 until one of the subarrays is exhausted.
- Add any remaining elements from the other subarray to the new array.

## Merging recursively

This process of merging continues recursively until all subarrays are merged back together, resulting in a fully sorted array or list. The recursive nature of merge sort allows it to efficiently sort large datasets.

## Time complexity

Merge sort has a time complexity of O(n log n), where n is the number of elements in the input array or list. This makes it one of the most efficient sorting algorithms available, especially for large datasets.

## Conclusion

Merge sort is a powerful sorting algorithm that follows the divide-and-conquer strategy to efficiently sort arrays or lists. Its simplicity and effectiveness make it a popular choice in various applications where sorting is required. By understanding how merge sort works and its time complexity, you can implement this algorithm in your own projects to achieve efficient sorting.