GDI golf

long.cpp

// stdafx.h isn’t needed.
// However, we DO need the line break after the include,
// even in the golf version.
#include <windows.h>
// _tmain => main; VC++ accepts both.
int main()
{
   HDC h = GetDC(0);
   // Remove i++ here …
   for (int i = 0; i < 50;){
       // 65793 == 0x010101; multiplying with 1…50 generates
       // grey tones and is much shorter than RGB macro use
       SelectObject(h, CreatePen(0, 9, i*65793));
       // i * 9 + 9 == i * 10
       // … add i++ here.
       Rectangle(h, i * 9, i * 9, i * 10, i++ * 10);
   }
}

short.cpp

#include <windows.h>
int main(){HDC h=GetDC(0);for(int i=0;i<50;){SelectObject(h,CreatePen(0,9,i*65793));Rectangle(h,i*9,i*9,i*10,i++*10);}}