希尔排序

#include 
using namespace std;

int main(void)
{
  int n;
  cin >> n;
  int arr[n];
  for (int i = 0; i < n; i++) cin >> arr[n];
  
  // 希尔排序
  for (int gap = n/2; gap > 0; gap = gap/2)
  {
    for (int i = gap; i < n; i++)
    {
      int value = arr[i];
      int p = i;
      while(p > 0 && (p-gap) >= 0 && arr[p-gap] > value)
      {
        arr[p] = arr[p-gap];
        p = p - gap;
      }
      arr[p] = value;
    }
  }
  
  for (int i = 0; i < n; i++) cout << arr[i] << ' ';
  cout << endl;
  return 0;
}