【手写系列】希尔排序

希尔排序:

/**
 * @author Jay
 * @date 2020/7/12 19:51
 * @Description:希尔排序
 */
public class shellSort {
    public int[] ShellSortSimple(int[] a) {
        for (int gap = a.length / 2; gap > 0; gap /= 2) {
            for (int i = gap; i < a.length; i++) {
                for (int j = i - gap; j > 0; j -= gap) {
                    if (a[j] > a[j + 1]) {
                        int temp = a[j];
                        a[j] = a[j + 1];
                        a[j + 1] = temp;
                    }
                }
            }
        }
        return a;
    }

    //位移法改变，效率增加
    public int[] ShellSort(int[] a) {
        for (int gap = a.length / 2; gap > 0; gap /= 2) {
            for (int i = gap; i < a.length; i++) {
                int j = i - gap;
                int temp = a[i];
                if (a[j] > a[j + 1]) {
                    while (j >= 0 && temp < a[j]) {
                        a[j] = a[j + 1];
                        j -= gap;
                    }
                    a[j] = temp;
                }
            }
        }
        return a;
    }
}