Sorting is a fundamental operation in computer science, and there are many algorithms designed to efficiently sort data. In this blog, we will discuss non-recursive sorting algorithms, which are algorithms that do not use recursion in their implementation.

Non-recursive sorting algorithms have the advantage of being more memory-efficient than recursive algorithms, as they do not use the system stack to manage the recursion. They can also be easier to implement and understand, as they do not require a deep understanding of recursion.

5 Non- Recursive Sorting Algorithms

Here are some commonly used non-recursive sorting algorithms:

Selection Sort

Selection Sort is a simple sorting algorithm that repeatedly selects the smallest element from an unsorted portion of the list and places it at the beginning of the sorted portion. This algorithm has a time complexity of O(n^2), making it inefficient for large data sets.

Insertion Sort

Insertion Sort works by iterating over each element in the list, comparing it to the previous element, and swapping it into the correct position. This algorithm has a time complexity of O(n^2), but is efficient for small data sets or partially sorted lists.

Bubble Sort

Bubble Sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order. This algorithm has a time complexity of O(n^2), and is not recommended for large data sets.

Merge Sort

Merge Sort is a divide-and-conquer algorithm that divides the input list into two halves, sorts them independently, and then merges the sorted halves. This algorithm has a time complexity of O(n log n), making it efficient for large data sets.

To implement merge sort non-recursively, we use an iterative approach instead of recursion. Instead of dividing the array into smaller subarrays recursively, we start with the smallest possible subarrays (each containing only one element) and gradually merge them to form larger sorted subarrays until the entire array is sorted.

Quick Sort

Quick Sort: Quick Sort is a divide-and-conquer algorithm that partitions the list into two sub-lists, according to a chosen pivot element. It then recursively sorts the sub-lists. This algorithm has a time complexity of O(n log n), but can degrade to O(n^2) in the worst-case scenario.

When selecting a sorting algorithm, it is important to consider the characteristics of the input data, such as size, distribution, and whether it is partially or fully sorted. Different algorithms may perform better on different types of data.

To implement Quick Sort non-recursively, we use a stack to simulate the recursive function calls. Instead of making recursive calls to sort the subarrays, we use a stack to keep track of the subarrays that still need to be sorted.

In conclusion, non-recursive sorting algorithms are a powerful tool in computer science, and understanding their strengths and weaknesses can help in selecting the most efficient algorithm for a given task.