porqueria de codigo

#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace System;
using std::cout;
using std::cin;
using std::endl;

short menu() {
    short *opcion = new short;
    do {
        cout << "1-Determinar el factorial de un numero : " << endl;
        cout << "2-Calcular de e^a : " << endl;
        cout << "3-Imprimir Rombo : " << endl;
        cout << "4-Salir : " << endl;
        cin >> *opcion;
    } while (*opcion < 1 || *opcion>4);
    return *opcion;
}
long factorial(short *nro) {
    short c = 1;
    long factorial(1);
    do {
        factorial *= c;
            ++c;
    } while (c <= *nro);
    return factorial;
}
long potencia(short *b, short *exp) {
    long r = 1;
    for (int c = 1; c <= *exp; ++c)
    {
        r *= *b;
    }
    return r;
}
void sumatoria(short *a, short *k){
    float r = 1;
    for (short c = 1; c <= *k; ++c)
        r += (float)potencia(a, &c) / (float)factorial(&c);
    cout << r;
}
void graficar(int l) {

    for (short cf = 1; cf<= l; cf++)
    {Console::SetCursorPosition(40-cf-1, cf);
        for (short cc = 1; cc <= 2*cf-1; cc++)
        {

            cout << cc;
        }
        cout<<endl;
    }
    //////
    for (short cf = 1; cf <= l; cf++)
    {
        Console::SetCursorPosition(40 - cf-1 , 2*l-cf);
        for (short cc = 1; cc <= 2 * cf - 1; cc++)
        {

            cout << cc;
        }
        cout << endl;
    }
}
short ingresarNro() {
    short nro;
    do{
        cout << "ingrese nro : ";
        cin >> nro;
    } while (nro < 0 || nro>10);
    return nro;
}
int main() {
    short op = menu();
    short *nro = new short;
    short *a = new short;
    short *k = new short;
    float *suma;
    switch (op) {
    case 1:
        *nro=ingresarNro();
        cout << "El factorial es : " << factorial(nro);break;
    case 2:
        *a = ingresarNro();
        *k = ingresarNro();
        sumatoria(a, k);break;
    case 3:
        *nro = ingresarNro();
        graficar(*nro);
    default:;
               }



    cin.ignore();
    cin.get();
    return 0;

}