Ejercicio Elimina Multiplos de tres

#include "stdafx.h"
#include <conio.h>
#include <iostream>
using namespace System;
using namespace std;

void GenerarArreglo(int *arr, int n)
{
    Random r;
    for (int i = 0; i < n; i++)
    {
        arr[i] = r.Next(1, 51);
    }
}
void ImprimirArreglo(int *arr, int &n)
{
    for (int i = 0; i < n; i++)
    {
        cout << arr[i] << endl;
    }
}
void EliminaMult(int *arr, int n)
{
    int cont=0, cont2=0;
    for (int i = 0; i < n; i++)
    {
        if (arr[i] % 3 == 0)
            cont++;
    }
    int *temp = new int[n - cont];
    for (int i = 0; i < n; i++)
    {
        if (arr[i] % 3 != 0)
        {
            temp[i-cont2] = arr[i];
        }
        else cont2++;
    }
    if (arr != NULL)
        delete[]arr;
    arr = temp;
    n = n - cont;
    cout << endl;
    ImprimirArreglo(arr, n);
}
int main()
{
    int n;
    cout << "Ingrese n: "<<endl;
    cin >> n;
    cout << endl;
    int *arreglo = new int[n];
    GenerarArreglo(arreglo, n);
    ImprimirArreglo(arreglo, n);
    EliminaMult(arreglo, n);
    _getch();
    return 0;
}