Ejercicio Mult Preguntar al prof.

#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;
    }
}
int* 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);
    return arr;
}
void OrdenarDesc(int *arr, int n)
{
    int aux;
    for (int i = 0; i < n-1; i++)
    {
        for (int j = i+1; j < n; j++)
        {
            if (arr[i] < arr[j])
            {
                aux = arr[i];
                arr[i] = arr[j];
                arr[j] = aux;
            }
        }
    }
    ImprimirArreglo(arr, n);
}
void InsertarEnPosicion(int *arr, int n, int num)
{
    int cont = 0;
    int *temp = new int[n+1];
    for (int i = 0; i < n; i++)
    {
        if (arr[i] >= num)
            temp[i] = arr[i];
        if (arr[i] <= num &&cont == 0)
        {
            temp[i] = num; cont++;
        }
        if (arr[i] <= num)
            temp[i + 1] = arr[i];
    }
    n++;
    if (temp[n-1] < 0||temp[n-1]>10000000) temp[n-1] = num;
    if (arr != NULL)
        delete[]arr;
    arr = temp;
    ImprimirArreglo(arr, n);
}
int main()
{
    int n, num;
    cout << "Ingrese n: "<<endl;
    cin >> n;
    cout << endl;
    int *arreglo = new int[n];
    GenerarArreglo(arreglo, n);
    ImprimirArreglo(arreglo, n);
    arreglo=EliminaMult(arreglo, n);
    cout << endl;
    OrdenarDesc(arreglo, n);
    cout << "Ingrese un numero: ";
    cin >> num;
    cout << endl;
    InsertarEnPosicion(arreglo, n, num);
    _getch();
    return 0;
}