C++. Вопрос с палиндромом

 #include <iostream> 
using namespace std; 
bool is_palindrome(int* box, const size_t n) { 
    auto beg = box; 
    auto end = box + n; 
    while (beg < --end) if (*beg++ != *end) return false; 
    return true; 
} 
void fill(int* box, const size_t n) { 
    cout << "Input " << n << " elements: "; 
    for (size_t i = 0; i < n; ++i) cin >> box[i]; 
} 
int main() { 
    const size_t n = 9; 
    int box[n]; 
    fill(box, n); 
    puts(is_palindrome(box, n) ? "Palindrome" : "Not palindrome"); 
}