Some time ago we have a discussion and now I am ready to present my algorithm for counting local mins. It is liniar for imperative case and in functially too (I hope). I spent hours of debugging on it... -- | Main entry point to the application. module Main where str = [5, 6, 7, 1, 0, 5, 3] norm :: ([a],[a]) -> ([a],[a]) norm (x,[]) = (take l1 x, take l2 $ reverse x) where l1 = length x `div` 2 l2 = length x - l1 norm ([],x) = (take l2 $ reverse x, take l1 x) where l1 = length x `div` 2 l2 = length x - l1 norm x = x insert :: (Ord a, Show a) => [a] -> Int -> ([(a, Int)],[(a, Int)]) -> ([(a, Int)],[(a, Int)]) insert [] _ x = x insert x p ([],[]) = ([(head x, p)],[]) insert x p (y,[]) = insert x p (norm (y,[])) insert x p (ys,z:zs) = if head x >= fst z then (ys,(head x, p):z:zs) else insert x p (ys,zs) delete :: (Ord a, Show a) => Int -> Int -> ([(a, Int)],[(a, Int)]) -> ([(a, Int)],[(a, Int)]) False = undefined delete p r ([],x) = delete p r (norm ([],x)) delete p r (x:xs,y) = if p > (snd x + r) then (xs,y) else (x:xs,y) getmin :: (Ord a, Show a) => ([(a, Int)],[(a, Int)]) -> a getmin ([],[]) = error "Getmin error" getmin ([],x) = getmin (norm ([],x)) getmin (x:xs,y) = fst x pass :: (Ord a, Show a) => [a] -> [a] pass [] = [] pass (x:xs) = xs minn :: Ord a => [a] -> [a] -> [a] minn x y = [] lmini :: (Ord a, Show a) => Int -> Int -> ([(a, Int)],[(a, Int)]) -> [a] -> [a] -> [a] lmini _ _ _ [] _ = [] lmini p r deq c l = if p < r then lmini (p+1) r (insert l p deq) c (pass l) else getmin deqn : lmini (p+1) r deqn (pass c) (pass l) where deqn = if p < (r*2) then insert l p deq else insert l p (delete (p-1) r deq) lmin :: (Ord a, Show a) => Int -> [a] -> [a] lmin r x = lmini 0 r ([],[]) x x main :: IO () main = do putStrLn "Min for list" putStrLn $ show str -- Regards, Marat. С уважением Марат.