Selection Sort : A Simple yet Powerful Algorithm

Selection sort is one of the most basic and popular sorting algorithms out there. It is a simple algorithm that works by repeatedly selecting the smallest element from an unsorted array and placing it at the beginning of the array until the array is sorted. It is a comparison-based algorithm, meaning that it compares elements to determine their order. Selection sort is a great algorithm for sorting small datasets, but it is not very efficient for large datasets.

How Does Selection Sort Work?

Selection sort works by iterating through an array and finding the smallest element. This element is then placed at the beginning of the array and the process is repeated until the array is sorted.

The algorithm can be broken down into four steps:

1. Find the smallest element in the array.
2. Swap the smallest element with the first element in the array.
3. Repeat steps 1 and 2 for the remainder of the array.
4. The array is now sorted.

Pseudocode

The following pseudocode outlines the selection sort algorithm:

SELECTION-SORT(A)
1  for i = 1 to A.length - 1
2      min = i
3      for j = i + 1 to A.length
4          if A[j] < A[min]
5              min = j
6      swap A[i] and A[min]
7  return A

Time Complexity

The time complexity of selection sort is O(n²). This means that the algorithm takes quadratic time to sort an array of size n. This makes selection sort an inefficient algorithm for sorting large datasets.

Conclusion

Selection sort is a simple yet powerful sorting algorithm. It is great for sorting small datasets, but it is not very efficient for large datasets. The time complexity of selection sort is O(n²), meaning that it takes quadratic time to sort an array of size n.