Implementing the Selection Sort Algorithm in C++

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 sequence until all elements are sorted. The basic steps are as follows: the outer loop controls the current starting position of the unsorted elements; the inner loop finds the minimum value among the remaining elements; the swap operation moves the minimum value to the current starting position; this process repeats until all elements are sorted. Taking the array {64, 25, 12, 22, 11} as an example, the process is demonstrated: when i=0, the minimum value 11 is found and swapped to the first position; when i=1, 12 is found and swapped to the second position; when i=2, 22 is found and swapped to the third position; no swap is needed when i=3, and the array is finally sorted. The C++ code is implemented with two nested loops: the outer loop controls the position i, the inner loop finds the index minIndex of the minimum value, and swaps arr[i] with arr[minIndex]. The time complexity is O(n²) and the space complexity is O(1). Selection sort is easy to implement and requires no additional space. It is suitable for sorting small-scale data and serves as a foundational example for understanding sorting algorithms.