插入排序（Java实现）

package unit_2;/** * 插入排序算法采用增量模式，每次把第j个数插入有序的A[0...j-1]中 生成另外一个有序的数组。 * 最佳情况复杂度：O(n) * 最坏情况复杂度：O(n^2) * @author WuNanliang * */public class InsertSorted {    public static void main(String[] args) {        int arr[] = { 12, 33, 22, 1, 23, 2, 4, 5, 6, 77, 66, 55, 890 };        insert_sort(arr);        for (int i = 0; i < arr.length; i++)            System.out.print(arr[i] + " ");        System.out.print("\n");        insert_sort_desc(arr);        for (int i = 0; i < arr.length; i++)            System.out.print(arr[i] + " ");    }    /**     * 排序算法 降序     *      * @param arr     */    private static void insert_sort_desc(int arr[]) {        if (arr == null || arr.length == 0)            return;        int len = arr.length;        int cursor = -1;        int key = 0;        for (int i = 1; i < len; i++) {            cursor = i - 1;            key = arr[i];            while (cursor >= 0 && arr[cursor] < key) {                arr[cursor + 1] = arr[cursor];                cursor = cursor - 1;            }            arr[cursor + 1] = key;        }    }    /**     * 插入排序算法     *      * @param arr     */    private static void insert_sort(int[] arr) {        if (arr == null || arr.length == 0)            return;        int len = arr.length;        int cursor = -1;        for (int i = 1; i < len; i++) {            int key = arr[i];            cursor = i - 1;            while (cursor >= 0 && arr[cursor] > key) {                arr[cursor + 1] = arr[cursor];                cursor = cursor - 1;            }            arr[cursor + 1] = key;        }    }}