Gauss.hs

import Control.Applicative ((<$>))
import Text.Printf (printf)

type Solution = Maybe [Double]

solve :: [[Double]] -> Solution
solve [[a, b]] = return [b / a]
solve (h@(x : xs) : t) = do
	let minor = transform h t
	if any isNull minor
	then Nothing
	else do
		solutions <- solve minor
		return $ (sum $ zipWith (*) xs (solutions ++ [-1.0])) / (negate x) : solutions

isNull :: [Double] -> Bool
isNull [x] = True
isNull (x:xs) = if x == 0 then isNull xs else False

transform :: [Double] -> [[Double]] -> [[Double]]
transform row = map $ elliminate row
  where
	elliminate :: [Double] -> [Double] -> [Double]
	elliminate (x : xs) (y : ys) =
		let factor = negate (y / x) in
		zipWith (+) (map (* factor) xs) ys

readNumList :: String -> [Double]
readNumList = map read . words

main :: IO ()
main = do
	[n, m] <- readNumList <$> getLine
	inp <- map readNumList <$> (sequence $ replicate (floor n) getLine)
	if n < m
	then putStrLn "INF"
	else case solve inp of
		Just solutions -> putStrLn "YES" >> (putStrLn . unwords . map (printf "%.8f") $ solutions)
		Nothing -> putStrLn "NO"