常用排序算法——希爾排序

#include <iostream>
using namespace std;

template <class T>
void shell_sort(T *a, int n)  
{  
    int j, gap;  

    for (gap = n / 2; gap > 0; gap /= 2)  
    {
        //從數組第gap個元素開始  
        for (j = gap; j < n; j++)
        {
            //每個元素與自己組內的數據進行直接插入排序  
            if (a[j] < a[j - gap])
            {  
               T temp = a[j];  
               int k = j - gap;  
               while (k >= 0 && a[k] > temp)  
               {
                   a[k + gap] = a[k];  
                   k -= gap;  
               }  
               a[k + gap] = temp;  
            }  
        }
    }
}  

int main()
{
    int size;
    cin >> size;
    int *arr = new int[size];
    for(int i = 0; i < size; ++ i)
        cin >> *(arr+i);
    shell_sort(arr, size);
    for(int i = 0; i < size; ++ i)
        cout << *(arr + i) << " ";
    cout << endl;
}