Динамическое распределение памяти

#include <iostream>
 
using namespace std;
 
int main()
{
    int n, arr;
    cin >> n;
    arr = new int *[n];
        {
{
    delete [] arr;
    system("pause");
}

#include <iostream>
 
int main()
{
    int n;
    bool right = true;
    std::cin >> n;
    int **arr = new int*[n];
    for (int i=0; i < n; i++)
    {
        arr[i] = new int[n];
        for (int j=0; j < n; j++)
            arr[i][j] = i*n + j + 1;
        for (int j=0; j < n; j++)
            std::cout << (right ? arr[i][j] : arr[i][n-j-1]) << " ";
        std::cout << std::endl;
        right ^= 1;
        delete [] arr[i];
    }
    delete [] arr;
}

#include <iostream>
#include <iomanip>
 
int** getSquareMatrix(int n)
{
    int **arr = new int * [n];
    for (int i = 0; i != n; ++i) arr[i] = new int [n];
    return arr;
}
 
void deleteSquareMatrix(int **arr, int n)
{
    for (int i = 0; i != n; ++i) delete[] arr[i];
    delete[] arr;
}
 
int main ()
{
    int n; std::cin >> n;
    int **arr = getSquareMatrix(n);
 
    for (int i = 0; i != n; ++i)
        for (int j = 0; j != n; ++j)
            arr[i][ i % 2 ? n - j - 1 : j ] = i * n + j;
 
    for (int i = 0; i != n; ++i, std::cout << std::endl)
        for (int j = 0; j != n; ++j)
            std::cout << std::setw(4) << arr[i][j];
 
    deleteSquareMatrix(arr, n);
    return 0;
}