选择排序

public class SelectionSort {

    public static void selectionSort(int[] arr) {
        if (arr == null || arr.length < 2) {
            return;
        }
        for(int i = 0; i < arr.length - 1; i++){ // i ~ N -1

            int minIndex = i;

            for (int j = i + 1; j < arr.length; j++) { // i ~ N - 1 上找最小值的下标

                minIndex = arr[j] < arr[minIndex] ? j : minIndex;
            }
            swap(arr, i, minIndex);

        }

    }

    public static void swap(int[] arr, int i, int j) {
        int tmp = arr[i];
        arr[i] = arr[j];
        arr[j] = tmp;
    }

    public static void main(String[] args) {
        int[] arr = new int[]{6, 8, 4, 3, 9, 7};
        SelectionSort.selectionSort(arr);
        System.out.print(arr[0]);
        for(int i = 1; i < arr.length; i++){
            System.out.print(", " + arr[i]);
        }
    }

}