A merge sort is a type of a divide and conquer algorithm used to sort a given array; this means that the array is divided into halves and then further sub-divided till division can no longer take place. … The sorted merge continues till all divisions of the array have been merged, giving us a sorted array.

## What is merge sort in Java with example?

Like QuickSort, Merge Sort is a **Divide and Conquer algorithm**. It divides the input array into two halves, calls itself for the two halves, and then merges the two sorted halves. The merge() function is used for merging two halves.

## How does a merge sort work java?

**Merge Sort** in **Java**

**Merge sort is**a “divide and conquer” algorithm wherein we first divide the problem into subproblems. …- For the recursive case, we get the middle index and create two temporary arrays l[] and r[].

## What is merge sort and how it works?

Merge sort is one of the most efficient sorting algorithms. It **works on the principle of Divide and Conquer**. Merge sort repeatedly breaks down a list into several sublists until each sublist consists of a single element and merging those sublists in a manner that results into a sorted list.

## What is merge sort used for?

Merge Sort is a sorting algorithm, which is commonly used in computer science. Merge Sort is a divide and conquer algorithm. It works **by recursively breaking down a problem into two or more sub-problems of the same or related type**, until these become simple enough to be solved directly.

## What are the four steps of the merge sort algorithm?

**Here’s how merge sort uses divide-and-conquer:**

- Divide by finding the number q of the position midway between p and r. …
- Conquer by recursively sorting the subarrays in each of the two subproblems created by the divide step. …
- Combine by merging the two sorted subarrays back into the single sorted subarray array[p..

## How do you write a merge sort algorithm?

Step 1 − if it is only one element in the list it is already sorted, return. Step 2 − divide the list recursively into two halves until it can no more be divided. Step 3 − **merge the smaller lists into new list in sorted order**.

## What is two way merge sort?

(algorithm) Definition: A k-way merge **sort that sorts a data stream using repeated merges**. It distributes the input into two streams by repeatedly reading a block of input that fits in memory, a run, sorting it, then writing it to the next stream.

## What is the time complexity of merge sort algorithm?

Merge Sort Time and Space Complexity

The time complexity of MergeSort is **O(n*Log n)** in all the 3 cases (worst, average and best) as the mergesort always divides the array into two halves and takes linear time to merge two halves.

## Is quicksort a stable sorting algorithm?

**Quick sort is not a stable algorithm** because the swapping of elements is done according to pivot’s position (without considering their original positions). A sorting algorithm is said to be stable if it maintains the relative order of records in the case of equality of keys.

## What happens in insertion sort?

Insertion sort is the **sorting mechanism where the sorted array is built having one item at a time**. The array elements are compared with each other sequentially and then arranged simultaneously in some particular order.

## What are the advantages of merge sort?

Merge sort is **more efficient and works faster than quick sort in case of larger array size or datasets**. Quick sort is more efficient and works faster than merge sort in case of smaller array size or datasets.

## Why is merge sort faster?

Merge sort requires a temporary array to merge the sorted arrays and hence it is not in-place giving Quick sort the advantage of space. … Locality of reference : **Quicksort in particular exhibits good cache locality** and this makes it faster than merge sort in many cases like in virtual memory environment.