{-# LANGUAGE NoMonomorphismRestriction #-}
import qualified Data.Set as S

main = narisavatKvadratiki

narisavatKvadratiki =
    flip mapM_ [razmer,razmer-odin.. -razmer] $ \yKoordinata ->
        flip mapM_ [-razmer..razmer] (\xKoordinata ->
            putStr [if S.member [xKoordinata,yKoordinata] treugolnichki
                       then chornayaTochka 
                       else pusto
                    ,pusto]) >> putChar novayaLiniya where
    treugolnichki = S.fromList $ popravitj $ zaeboshitTreugolnichki 3 [[razmer*cos ugol,razmer*sin ugol] | ugol <- [pi/2,pi/2+2*pi/3,pi/2+4*pi/3]]
    zaeboshitTreugolnichki glubina koordinati@[verx,levo,pravo]
        | glubina==nolj = []
        | otherwise = (obzmeitj koordinati >>= uncurry zaeboshitLiniyu) ++ 
                      ([[verx,verxlevo,pravoverx],
                        [verxlevo,levo,levopravo],
                        [pravoverx,levopravo,pravo]] >>= zaeboshitTreugolnichki (glubina-odin)) where
            [verxlevo,levopravo,pravoverx] = map (uncurry srednyaaTochka) (obzmeitj koordinati)
        
zaeboshitLiniyu odin dva = 
    [zipWith (+) odin [dlina*cos ugol,dlina*sin ugol] | dlina <- [nolj,prirashenie..rasstojanie]] where
        ugol = vicheslitUgol odin dva
        rasstojanie = vicheslitRasstoyanie odin dva
    
vicheslitRasstoyanie [xKoordinata1,yKoordinata1] [xKoordinata2,yKoordinata2] = 
    sqrt $ (xKoordinata1-xKoordinata2)^dva + (yKoordinata1-yKoordinata2)^dva
vicheslitUgol [xKoordinata1,yKoordinata1] [xKoordinata2,yKoordinata2] = 
    atan2 (yKoordinata2-yKoordinata1) (xKoordinata2-xKoordinata1)
srednyaaTochka [xKoordinata1,yKoordinata1] [xKoordinata2,yKoordinata2] = 
    [(xKoordinata1+xKoordinata2)/dva,(yKoordinata1+yKoordinata2)/dva]

obzmeitj spisok = zip spisok (tail spisok) ++ [(head spisok,last spisok)]
popravitj = map (map round)
    
razmer = 20
prirashenie = 0.3
nolj:odin:dva:_ = [0..]
nachalo = [nolj,nolj]
[chornayaTochka,pusto,novayaLiniya] = "# \n"