希尔排序

public static int [] shellSort(int [] array){
        //根据array数组的长度，对待排序的数组进行分组,分组的总数等于总长度的一半
        int group = array.length;
        while(group >= 1){
            group /= 2;
            for (int i = group; i < array.length; i++) {
                int shouldSort = array[i];
                int beforeShouldIndex = i - group;
                while (beforeShouldIndex > 0 && shouldSort < array[beforeShouldIndex]){
                    array[beforeShouldIndex + group] = array[beforeShouldIndex];
                    beforeShouldIndex -= group;
                }
                array[beforeShouldIndex + group] = shouldSort;
            }
        }
        return array;
    }