def selection_sort(collection: list[int]) -> list[int]:
    """
    Sorts a list in ascending order using the selection sort algorithm.

    :param collection: A list of integers to be sorted.
    :return: The sorted list.

    Examples:
    >>> selection_sort([0, 5, 3, 2, 2])
    [0, 2, 2, 3, 5]

    >>> selection_sort([])
    []

    >>> selection_sort([-2, -5, -45])
    [-45, -5, -2]
    """

    length = len(collection)
    for i in range(length - 1):
        min_index = i
        for k in range(i + 1, length):
            if collection[k] < collection[min_index]:
                min_index = k
        if min_index != i:
            collection[i], collection[min_index] = collection[min_index], collection[i]
    return collection


if __name__ == "__main__":
    user_input = input("Enter numbers separated by a comma:\n").strip()
    unsorted = [int(item) for item in user_input.split(",")]
    sorted_list = selection_sort(unsorted)
    print("Sorted List:", sorted_list)

Problem Statement

Given an unsorted array of n elements, write a function to sort the array

Approach

• select the smallest element from the array
• put it at the beginning of the array
• then select the smallest array from the remaining unsorted list
• append it to the sorted array at the beginning
• keep doing this for every element of the array
• repeat the above process n times

Time Complexity

O(n^2) Worst case performance

O(n^2) Best-case performance

O(n^2) Average performance

Space Complexity

O(1) Worst case

Example

arr[] = {80, 10, 40, 30}
Indexes: 0   1   2   3    

1. Index = 0
	Select the minimum number from the array (between index 0-3), ie, 10
2. Swap 10  and 80 (arr[0])
3. The array now is {10, 80, 40, 30}

4. Index = 1
	Select the minimum number from the array (between index 1-3), ie, 30
5. Swap 30 and 80 (arr[1])
6. The array now is {10, 30, 40, 80}

7. Index = 2
	Select the minimum number from the array (between index 2-3), ie, 40
8. Swap 40 and 40 (arr[2])
9. The array now is {10, 30, 40, 80}

The array is now sorted.

Video Explanation

A video explaining the Selection Sort Algorithm

Animation Explanation

• Tute Board