6 Basic Different Types of Sorting Algorithms Explained in Detail

What is Sorting Algorithms?

Sorting is an operation of arranging the elements in a particular order.

Examples:

1) Arranging numbers in descending or ascending order.

1, 4, 5, 5, 67, 245, 456 // sorted in ascending order

2) In case of a set of characters, ordering elements in alphabetic order.

a, c, f, k, m, x, z //sorted in alphabetic order

One of the most common tasks that everyone performs in their daily life is searching and sorting.

Likewise, the computer also performs these tasks several times for different operations. A real-life example would be a dictionary, where the words are stored in alphabetical order, so searching becomes easier.

This means the smallest data element can be searched from a huge data repository if the data is stored in a sorted manner.

Different Types of Sorting Algorithms in Data Structure

In data processing, there are various sorting methods and techniques that are not only used for sorting algorithms but are also used for analyzing the performance of other algorithms. In this post, you will find a brief description of the different types of sorting algorithms.

Popular sorting algorithms:

Sorting algorithms can be categorized as

• Simple sorts
• Efficient sorts

Simple Sorts

These types of algorithms are efficient on the small amount of data but cannot handle large data. They are fast and efficient due to low overhead. Two simplest sort algorithms are insertion sort and selection sorts

1. Insertion sort

Insertion is the most basic sorting algorithm which works quickly on small and sorted lists. It takes elements one by one from the list and inserts them in the correct order in the new sorted list. Shell sort is another type of insertion sort which is more useful for larger lists.

In the insertion sort algorithm, every step moves an element from the unsorted section to sorted section until all the elements are sorted in the list.

Algorithm- Step by step procedure:

• Step 1: Assume that the first element in the list is in the sorted section of the list and remaining all elements are in the unsorted section.
• Step 2: Consider the first element from the unsorted list and insert that element into the sorted list in the order specified (ascending or descending)
• Step 3: Repeat the above steps until all the elements from the unsorted list are moved to the sorted list.

Refer:

• Insertion Sort in Python

2. Selection sort

Selection sort is another comparison sort algorithm that compares a single element with all the other elements from the list. It is not efficient on large lists and is used as a part of complicated algorithms. It is similar to insertion sort but uses fewer swaps. So, it is useful for those programs where swaps are expensive.

Algorithm- Step by step procedure

• Step 1: Take the first element of the list
• Step 2: Compare the first element with all other elements in the list.
• Step 3: While comparing if any element is smaller than the selected element (ascending order), then these two are swapped.
• Step 4: Repeat the same process with all the positions in the list until the entire list is sorted.

Refer:

• C Program for Selection Sort
• Python Program for Selection Sort

3. Bubble Sort Algorithm

Bubble sort algorithm is easy to understand from the example itself. Please refer to the bubble sort algorithm explained with an example.

Efficient sorts

Practical sorting algorithms are usually based on algorithms with average time complexity. Some most common of these are merge sort, heap sort, and quicksort.

These algorithms can be used on large lists and complicated programs but each of them has its own drawbacks and advantages. Some may require additional space or more iterations, thus resulting in more complex algorithms.

Let’s have a look at these efficient sorting algorithms along with the step by step process.

4. Merge sort

Merge sort algorithm compares two elements of the list and then swaps them in the order required (ascending or descending). It applies the divide and rule concept. Merge sort works on sequential access and can work on large lists. This algorithm is popularly used in practical programming as it is used in the sophisticated algorithm Timsort. Timsort is used for standard sorting in languages such as Python and Jana. Merge sort algorithm is itself a standard routine in Perl.

Algorithm- Step by step procedure:

• Step 1: Divide the list recursively into two or more sub-problems until it can no more be divided
• Step 2: Solve the sub-problems until it is reached to the base case
• Step 2: Merge the smaller lists into the new list in sorted order

5. Heapsort

Heapsort is an advanced and efficient version of the selection sort algorithm. It works similarly by sorting the elements in the ascending or descending order by comparing but this is done by using a data structure called a heap, which is a special tree base structure. Heap has the following properties:

• It is a complete tree
• Root has a greater value than any other element in the subtree

Algorithm- Step by step procedure:

• Step 1: Form a heap from the given data
• Step 2: Remove the largest item from the heap
• Step 3: From the remaining data reform the heap
• Step 4: Repeat step 2 and 3 until all the data is over

6. Quicksort algorithm

Quicksort is similar to merge sort which uses divide and conquers technique. Thus it is a recursive algorithm. But quicksort performs in a little different manner than mergesort does. In the merge sort, the work does not happen in the division stage but it happens in the combined stage. But in quicksort it is totally opposite, everything happens in the division stage.

Algorithm- Step by step process:

• Step 1: Divide the list by any chosen element and call it a Pivot element. Rearrange the elements, all the elements that are less than equal to the pivot element must be in left and larger ones on the right. This procedure is called Partitioning.
• Step 2: Conquer which mean recursively ordering the subarrays
• Step 3: There is nothing left in the combined stage as the conquer stage organizes everything. The smaller or equal elements to the pivot are organized at the left side and larger elements are organized at the right.

Check out complete QuickSort tutorial– explained with an example, programming and complexity.

Final thoughts

These are some common and highly used different types of sorting algorithms in the data structure. There are many more sorting algorithms and they can be combined for large data sets that exceed system memory and time. I hope you have got an idea of the various types of sorting algorithms which can be used as a part of bigger programs.

Naina Makhija

She is a content writer at CSEstack and was previously a copywriter TCS. She has completed her Masters in Computer Application and has good technical knowledge. She paints, reads and tries out new DIYs. When she is not doing all those, She is either cooking new cuisines or traveling to new destinations.