时间复杂度O(n^2)
    Java实现:
    根据最大和最小索引分别实现

    1. public static <E extends Comparable<E>> void sort(E[] nums) {
    2.         int length = nums.length;
    3.         //nums[0...i]有序  nums[i...n)无序
    4.         for (int i = 0; i < length; i++) {
    5.             //选择nums中最小值的索引
    6.             int minIndex = i;
    7.             for (int j = i; j < length; j++) {
    8.                 if (nums[j].compareTo(nums[minIndex]) < 0) {
    9.                     minIndex = j;
    10.                 }
    11.                 E num = nums[i];
    12.                 nums[i] = nums[minIndex];
    13.                 nums[minIndex] = num;
    14.             }
    15.         }
    16.         System.out.println(Arrays.toString(nums));
    17.     }
    1. public static <E extends Comparable<E>> void sort2(E[] nums) {
    2.         int length = nums.length - 1;
    3.         //nums[0...i]无序  nums[i...n)有序
    4.         for (int i = length; i >= 0; i--) {
    5.             //当前最大索引
    6.             int maxIndex = i;
    7.             for (int j = i; j >= 0; j--) {
    8.                 if (nums[j].compareTo(nums[maxIndex]) > 0) {
    9.                     maxIndex = j;
    10.                 }
    11.             }
    12.             swap(nums, i, maxIndex);
    13.         }
    14.         System.out.println(Arrays.toString(nums));
    15.     }
    17.     private static <E> void swap(E[] nums, int i, int minIndex) {
    18.         E num = nums[i];
    19.         nums[i] = nums[minIndex];
    20.         nums[minIndex] = num;
    21.     }
    1.  public static void main(String[] args) {
    2.         Integer[] nums = {4, 2, 6, 3, 5, 1};
    3.         sort(nums);
    4.         sort2(nums);
    5.     }

    go实现:

    1. func main() {
    2.     sort([]int{4, 2, 6, 3, 5, 1})
    3. }
    5. func sort(nums []int) {
    6.     length := len(nums)
    7.     for i := 0; i < length; i++ {
    8.         minIndex := i
    9.         for j := i; j < length; j++ {
    10.             if nums[j] < nums[minIndex] {
    11.                 minIndex = j
    12.             }
    13.             num := nums[i]
    14.             nums[i] = nums[minIndex]
    15.             nums[minIndex] = num
    16.         }
    17.     }
    18.     fmt.Println(nums)
    19. }

    项目demo