希尔排序

/* 插入排序的变种，通过增量这一特性，减少了数据比较和移动次数，是一种优化的插入排序 */
void shellSort(std::vector<int>& vec)
{
        int rate = 2;
        int increNum = vec.size() / rate;
        while(increNum)
        {
                for (int i = increNum; i < vec.size(); i++)
                {
                        int tmp = vec[i];
                        int j = i - increNum;
                        for (; j >= 0; j -= increNum)
                        {
                                if (vec[j] <= tmp)
                                {
                                        break;
                                }
                                else
                                {
                                        vec[j + increNum] = vec[j];
                                }
                        }
                        vec[j+increNum] = tmp;
                }

                rate *= 2;
                increNum = vec.size() / rate;
        }

}