# What is the difference between Quicksort and Merge Sort

The main difference between quicksort and merge is that quicksort sorts the elements by comparing each element to an element called a pivot, while mergesort splits the array into two subarrays over and over again until there is one element left. What is the difference between Quicksort and Merge Sort

Sorting is the method of organizing data in a particular order. When organizing the data, it is possible to consider the numerical or lexicographical order. Sorting helps to find and access data elements quicker and faster. There are various sorting algorithms, and Quicksort and Merge Sort are two of them.

### Key Areas Covered

1. What is Quicksort
– Definition, Functionality
2. What is Merge Sort?
– Definition, Functionality
3. What is the difference between Quicksort and Merge Sort
– Key Differences Comparison

## What is Quicksort?

Quicksort is an internal algorithm that uses the “divide and conquer” technique. It is also called a partition swap type . It uses a key element called a pivot to compare and partition the elements of the array. Items with a value less than the pivot go to the left side of the pivot, while items with a value greater than the pivot go to the right side of the pivot. The left section is called the left partition, and the right section is called the right partition.

See the example below.

36 34 43 11 15 20 28 45 27 32

Consider 32 to be the pivot, and consider 36 and 27. The conditions 36 < pivot, 27 > pivots are false. Therefore, we can interchange these two values. Now the list is as follows.

27 34 43 11 15 20 28 45 36 32

Consider the values ​​34 and 45. Considering 34 < pivot, the condition is false. Similarly, 45 > The pivot condition is true. Now, we can go from 45 to 28. Let’s consider 34 and 28. 34 < pivot is false and 28 > pivot is false So we can swap 34 and 28.

27 28 43 11 15 20 34 45 36 32

Consider 43 and 20. 43 < pivot is false. 20 > pivot is false So we can swap the two numbers. Now the list is as follows.

27 28 20 11 15 43 34 45 36 32

Now consider 11 and 15. 11 < pivot is true. We can consider 15. It is less than 32. It is the overlapping point, and we can place 32 as follows.

27 28 20 11 15 32 43 34 45 36

Now the numbers on the left side of the pivot are smaller than the pivot, and the right side of the pivot is larger than the pivot. We can apply quicksort to the left and right partitions to sort the entire list.

## What is fusion sorting?

Merge Sort is an external algorithm that uses the “divide and conquer” technique. The matrix is ​​divided into two sections. Sorts each array and combines them to form the sorted array. Merge sorting requires additional storage to sort the auxiliary array.

Consider 38 27 43 3. We can split it into two arrays again. They are 38 27 and 43 3. 38 27 splits into 38 and 27, while 43 3 splits into 43 and 3. Sorting 38 and 27 gives 27 38. Sorting 43 3 gives 3 43. It is now possible to combine 27 38 and 3 43 After sorting them, we get an array like 3 27 38 43.

Similarly, consider 9 82 10. We can split it into two arrays again. They are 9 82 and 10. 9 82 splits into 9 and 82. Also, there is the number 10 in the other array. 9 and 82 are classified as 9 82. Therefore, this array and the array with value 10 combine to give 9 10 and 82.

## Difference between Quicksort and Merge Sort

### Definition

Quicksort is an efficient sorting algorithm, which serves as a systematic method of placing the elements of an array in order. In contrast, merge sort is an efficient, general-purpose, comparison-based sort algorithm. Therefore, this is the fundamental difference between quicksort and merge sort.

### functionality

Above all, functionality is the main difference between quick sort and merge sort. Quicksort sorts the elements by comparing each element to the pivot, while merge sort splits the array into two subarrays (n/2) over and over again until one element remains.

### Request

Also, while quicksort is suitable for small arrays, merge sort works for any type of array.

### Speed

Another difference between quicksort and merge is that quicksort works faster for small data sets, while merge sort works at a constant speed for all data sets.

### space requirement

On the other hand, space requirement is also an important difference between quicksort and merge. Quicksort requires minimal space compared to merge sort.

### Efficiency

Also, quicksort is not efficient for large arrays, but merge sort is more efficient than quicksort. Thus, this is another difference between quick sort and merge sort.

### conclusion

In short, the main difference between quicksort and merge is that quicksort sorts the elements by comparing each element to an element called a pivot, while merge sort divides the array into two subarrays over and over again until there is one element left.