希尔排序

void shellsort1(int a[], int n)
{
int i, j, gap;


for (gap = n / 2; gap > 0; gap /= 2) //步长
for (i = 0; i < gap; i++)        //直接插入排序
{
for (j = i + gap; j < n; j += gap) 
if (a[j] < a[j - gap])
   {
int temp = a[j];
int k = j - gap;
while (k >= 0 && a[k] > temp)
{
a[k + gap] = a[k];
k -= gap;
}
a[k + gap] = temp;
}
}
}