Make a DLL Hack

#include <Windows.h>
#include <stdio.h>
#include <iostream>

using namespace std;

DWORDLONG Pointer = 0x??????; // Pointer adress

int deger = ????; // new value

DWORD WINAPI Hile(LPVOID lpParam)
{
while (1)
{
HANDLE GAME = GetCurrentProcess();
WriteProcessMemory(Game, (LPVOID)Pointer, &deger, sizeof(deger),0);
}
return 0;
}

BOOL WINAPI DLLMain(HINSTANCE hModule, DWORD dwAttached, LPVOID lpReserved)
{
if (dwAttached == DLL_PROCESS_ATTACH)
{
CreateThread(NULL, 0, &Hile, NULL, 0, NULL);
}
return 1;
}

im still new but why r u including these:
#include <stdio.h>
#include <iostream>

using namespace std;

I'm new to C#, where can you put this source code ?