copying Vector elements into Dynamic Array

/* C++ Primer - 4/e

 * chapter 4- Arrays & Pointers, exercise 4.28
 * STATEMENT
 * write a programme to read the standard input and build a vector
 of integers from values that are read. allocate an array of the same
 size as the vector and copy elements from the vector into the array

 */

#include <iostream>
#include <vector>

int main()
{
  int iv;
  std::vector<int> ivec;

  while(std::cin >> iv)
    {
      ivec.push_back(iv);
    }

  const size_t arr_sz = ivec.size() + 1;
  int* pdarr = new int[arr_sz];
  int* pbegin = pdarr;
  /* we will use "pbegin" to print the array elements later */

  /* assign elements from vector to the dynamic array */
  for(std::vector<int>::const_iterator iter=ivec.begin();
 iter != ivec.end(); ++iter)
    {
      *pdarr++ = *iter;
    }

  /* printing the elements of arrar */
  std::cout << "printing array elements: ";
  for(int* q = pbegin; q != pbegin + arr_sz; ++q)
    {
      std::cout << *q << " ";
    }

  std::cout << std::endl;
  
  return 0;
}

======== OUTPUT ===========
~/programming/cpp $ g++ -ansi -pedantic -Wall -Wextra ex_04-28.cpp
~/programming/cpp $ ./a.out
2
3
-9
8
printing array elements: 2 3 -9 8 0
~/programming/cpp $

i have 2 questions:

1.) i have used "vecotor size + 1" for array size but i did not enter last
character as NULL. does the programme add it to the end of array itself
automatically ?

2.) output contains an extra integer in the end, the zero, 0. i am not
letting the pointer slipping-off the end of array because i used "q !=
pbegin + arr_size" then from where the zero came ?

--
-- http://arnuld.blogspot.com