Implementing the Selection Sort Algorithm with Python

Selection sort is a simple and intuitive sorting algorithm. Its core idea is to repeatedly select the smallest (or largest) element from the unsorted elements and place it at the end of the sorted portion until the entire array is sorted. The steps are as follows: initially, assume the current element is the smallest, traverse the unsorted portion to find a smaller element, swap it to the end of the sorted portion, and repeat until completion. In Python implementation, the outer loop variable `i` controls the end of the sorted portion (ranging from 0 to n-2). The inner loop variable `j` traverses the unsorted portion (from i+1 to n-1) to find the position `min_index` of the smallest element. Finally, swap `arr[i]` with `arr[min_index]`. For the test array [64, 25, 12, 22, 11], the sorted result is [11, 12, 22, 25, 64]. It has a time complexity of O(n²), a space complexity of O(1), and is an in-place sorting algorithm. Its characteristics are: simple to understand, but unstable (the order of identical elements may be swapped), and suitable for small-scale data.