Máximos locales de una matriz

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1. Haskell

   import Data.Array import qualified Data.Array as A import qualified Data.Map as M maximosLocales :: Matriz Int -> [((Int,Int),Int)] maximosLocales a = M.elems -- aquellos ... $ M.mapMaybeWithKey condicion -- ... que cumplen la condición ... $ M.fromListWith maximo dobleKeys -- ... seleccionando el máximo por clave where -- para cada clave, se selecciona aquella de mayor valor maximo a b = if snd a < snd b then b else a -- con la condición de que el máximo sea aquel con la misma clave condicion k e@(q, _) = if k == q then Just e else Nothing -- un valor ((x, y), v) será evaluado en cada clave (x + dx, y + dy) dobleKeys = [((x + dx, y + dy), (k, v)) | (k@(x, y), v) <- A.assocs a , dx <- [-1..1], dy <- [-1..1]]

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   import Data.Array import qualified Data.Array as A import qualified Data.Map as M   maximosLocales :: Matriz Int -> [((Int,Int),Int)] maximosLocales a =     M.elems                           -- aquellos ...   $ M.mapMaybeWithKey condicion     -- ... que cumplen la condición ...   $ M.fromListWith maximo dobleKeys -- ... seleccionando el máximo por clave     where     -- para cada clave, se selecciona aquella de mayor valor     maximo a b = if snd a < snd b then b else a          -- con la condición de que el máximo sea aquel con la misma clave     condicion k e@(q, _) = if k == q then Just e else Nothing       -- un valor ((x, y), v) será evaluado en cada clave (x + dx, y + dy)     dobleKeys = [((x + dx, y + dy), (k, v)) | (k@(x, y), v) <- A.assocs a                                             , dx <- [-1..1], dy <- [-1..1]]

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2. Haskell

   import Data.Array type Matriz a = Array (Int,Int) Int maximosLocales :: Matriz Int -> [((Int,Int),Int)] maximosLocales p = [(k,p!k)| k <- indices p, all (< p!k) (vecinos p k)] vecinos :: Matriz Int -> (Int,Int) -> [Int] vecinos p (i,j) = [p!k| k<-xs,k/=(i,j)] where xs = filter (\x-> inRange (bounds p) x) [(i+a,j+b)|a<-ys,b<-ys] ys = [-1,0,1]

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   import Data.Array type Matriz a = Array (Int,Int) Int   maximosLocales :: Matriz Int -> [((Int,Int),Int)] maximosLocales p = [(k,p!k)| k <- indices p, all (< p!k) (vecinos p k)]   vecinos :: Matriz Int -> (Int,Int) -> [Int] vecinos p (i,j) = [p!k| k<-xs,k/=(i,j)]             where xs = filter (\x-> inRange (bounds p) x) [(i+a,j+b)|a<-ys,b<-ys]                   ys = [-1,0,1]

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3. Haskell

   import Data.Array type Matriz a = Array (Int,Int) Int maximosLocales :: Matriz Int -> [((Int,Int),Int)] maximosLocales p = [((i,j),k) | ((i,j),k) <- assocs p, all (<k) (vecinos p (i,j))] where vecinos p (i,j) = [p!(a,b) | a <- [i-1..i+1], b <- [j-1..j+1], a `notElem` [0,n+1], b `notElem` [0,m+1], (a,b) /= (i,j)] (n,m) = snd $ bounds p

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   import Data.Array type Matriz a = Array (Int,Int) Int   maximosLocales :: Matriz Int -> [((Int,Int),Int)] maximosLocales p =     [((i,j),k) | ((i,j),k) <- assocs p, all (<k) (vecinos p (i,j))]     where vecinos p (i,j) = [p!(a,b) | a <- [i-1..i+1],                                        b <- [j-1..j+1],                                        a `notElem` [0,n+1],                                        b `notElem` [0,m+1],                                        (a,b) /= (i,j)]           (n,m) = snd $ bounds p

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4. Haskell

   import Data.Array type Matriz a = Array (Int,Int) Int maximosLocales :: Matriz Int -> [((Int, Int), Int)] maximosLocales=(\w->[k|k@((x,y),n)<-w ,null[1|((u,v),m)<-w,n<=m,elem(abs$x-u,abs$y-v)$zip[1,0,1][0,1,1]]]).assocs

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   import Data.Array   type Matriz a = Array (Int,Int) Int   maximosLocales :: Matriz Int -> [((Int, Int), Int)] maximosLocales=(\w->[k|k@((x,y),n)<-w                       ,null[1|((u,v),m)<-w,n<=m,elem(abs$x-u,abs$y-v)$zip[1,0,1][0,1,1]]]).assocs

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5. Haskell

   import Data.Array type Matriz a = Array (Int,Int) Int maximosLocales :: Matriz Int -> [((Int,Int),Int)] maximosLocales p = [a | a <- assocs p, maximoLocal a] where maximoLocal ((i,j),k) = k > maximum [p!(i+x,j+y) | x <- ns, y <- ns, not (x == 0 && y == 0), inRange (bounds p) (i+x,j+y)] ns = [-1,0,1]

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   import Data.Array   type Matriz a = Array (Int,Int) Int   maximosLocales :: Matriz Int -> [((Int,Int),Int)] maximosLocales p = [a | a <- assocs p, maximoLocal a]     where maximoLocal ((i,j),k) =               k > maximum [p!(i+x,j+y) | x <- ns,                                          y <- ns,                                          not (x == 0 && y == 0),                                          inRange (bounds p) (i+x,j+y)]           ns = [-1,0,1]

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