C++ Iterative Factorial Algorithm: Console Closing Issue, For Loop, Long Int Syntax

I have presented an algorithm that calculates strongly iteratively in C++.
Problem:
-the code compiles and displays on the screen, but after entering the number it closes the console window and that's it;
-gives him a number for n! and end of display;
-I tried adding the library [#include ], but it didn't help to display the results;
- the factorial function in braces should have a good syntax because I rewrote it based on the book;
- preferably the algorithm should be built on the [for] loop;
-searching in google, I found little about it, so I started to write it myself, but it doesn't want to work, there is an error somewhere.

[Code for factorial iteratively in C++]

[code:1:119d82eecd]#include
#include
#include
using namespace std;


long silnia(int liczba )
{
long int silnia=1;
for(int i=2;i n;
cout

No sense - first you call the function, then you get the value from the keyboard on which this function is to work, and at the end you display what the user typed...

[code:1:ac360adee9]cout > n;
cout

[code:1:2223e695e7]#include
#include
#include
using namespace std;


long silnia(int liczba )
{
long int silnia=1;
for(int i=2;i n;
//jesli n to zero lub liczba ujemna
if (n == 0 || n < 0)
{
cout

Everything is ok. The program compiles but does not display the results.

This one may work:
[code:1:e6b4ea4290]#include
#include

using namespace std;

long silnia(int liczba )
{
long int silnia=1;
for(int i=2;i n;
cout

I really missed this instruction and that was the problem. The function counts well is ok. And how to protect it so that it does not calculate n

Maybe I can help

[code:1:37fde233f7]

#include
#include

using namespace std;

long silnia(int liczba )
{
long int silnia=1;
if (liczba

Compiling, please, compiling!

Can you read messages? It tells you that you didn't declare the variable n...

Tell me where this 'n' should be declared


Maybe it's hard to see, but something else always came out with the error. Where is this minor error?

It should be declared before using it, i.e. a line before this error

[code:1:c870f2ec19]
#include
#include

using namespace std;

long silnia(int liczba )
{
long int silnia=1;
if (liczba

When I get up in the morning, I'll let you know if it works in DEV C++. ok :D

Added after 23 [minutes]:

Do you know any code to find the roots of a quadratic equation using a function as well. Regards hey