Selection sort algorithm is a popular sorting algorithm used in the field of data structure. It is a simple and intuitive sorting technique that works by dividing the input array into two parts: the sorted part and the unsorted part.
The algorithm repeatedly selects the smallest (or largest, depending on the desired order) element from the unsorted part and swaps it with the first element of the unsorted part. This process continues until the entire array is sorted.
How does Selection Sort Algorithm work?
The selection sort algorithm can be implemented in a step-by-step manner:
First, find the minimum element in the unsorted part of the array.
Swap this minimum element with the first element of the unsorted part.
Now, consider the next element in the unsorted part and repeat steps 1 and 2 until all elements are sorted.
This algorithm works by iteratively finding and swapping elements to gradually build a sorted portion of the array. The selection sort algorithm has a time complexity of O(n^2), making it inefficient for large datasets. However, it performs well for small datasets or arrays that are almost sorted.
To better understand how selection sort works, let’s consider an example:
Input Array: [5, 3, 8, 4, 2]
In each iteration of selection sort:
- Iteration 1:
[2, 3, 8, 4, 5]
- Iteration 2:
[2, 3, 8, 4, 5]
- Iteration 3:
[2, 3, 4, 8,
- Iteration 4:
2, 3, 4,
The array is now sorted in ascending order.
The selection sort algorithm is a simple and easy-to-understand sorting technique. Although it may not be the most efficient algorithm for large datasets, it can be useful for small datasets or arrays that are already partially sorted. Understanding different sorting algorithms is crucial in the field of data structure as it helps in choosing the most appropriate algorithm for specific scenarios.