решето эратосфена

#include <iostream>
#include <cmath>
using namespace std;

void eratosfen (int *arr, int n)
{
  int p = 0;

  for (int p = 2; p < n + 1; p++)
  {
    if (arr[p] != 0)
    {
      cout << arr[p] << " ";
      for (int j = p*p; j < n + 1; j += p)
        arr[j] = 0;
    }
  }
}

int main()
{
  int n = 0;
  cin >> n;

  int *arr = new int[n+1];

  for (int i = 0; i < n + 1; i++)
  {
      arr[i] = i;
     cout << arr[i] << " ";
   }
  cout << endl;

  eratosfen(arr, n+1);
}