数据结构 希尔(shell)排序

#include<stdio.h>
void ShellInsert(int a[],int dk,int length)
{
int i,j;
for(i=dk+1;i<=length;i++)
{   
if(a[i]<a[i-dk])
{
a[0]=a[i];
   for(j=i-dk;j>0&&a[0]<a[j];j-=dk)
   a[j+dk]=a[j];
     a[j+dk]=a[0];
}
     
    
}
}
void ShellSort(int a[],int length)
{   
    int dk,k;
for(dk=(length+1)/2;dk>=1;dk=dk/2)
{  ShellInsert(a,dk,length);
     for(k=1;k<=length;k++)
  {
printf("%d ",a[k]);
  }
  printf("\n");
}
}
int main()