spoj l1 = [y | x<-l1, y<-x]

delioci n = [x | x<-[1..n], n `mod` x == 0]

prosti n = [x | x<-[1..n], [y | y<-[1..x], x `mod` y == 0]==[1,x]]

prviprosti n = take n [x | x<-[1..], [y | y<-[1..x], x `mod` y == 0]==[1,x]]

pitagorine n = [(x,y,z) | x<-[1..n], y<-[1..n], z<-[1..n], x^2+y^2==z^2]

savrseni n = [x | x<-[1..n], sum [y | y<-[1..x-1], x `mod` y ==0] == x]

qsort [] = []
qsort (h:t) = qsort [x|x<-t,x<h] ++ [h] ++ qsort [x| x<-t, x>=h]

--Main> (\x -> x+1) 4
--5
--Main> (\x y-> x+y-1) 4 4
--7
--Main> 

mapiranje :: [a]->(a->b)->[b]
mapiranje [] f = []
mapiranje (h:t) f = (f h):(mapiranje t f)

--ugradjena funkcija map

--Main> mapiranje [1,2,4,5] (\x -> x+1)
--[2,3,5,6]
--Main> mapiranje [[1,2],[4,5,4]] (\x -> sum x)
--[3,13]

filtriraj :: [a]->(a->Bool)->[a]
filtriraj [] _ = []
filtriraj (h:t) f = if f h then h:(filtriraj t f) else filtriraj t f

--ugradjena funkcija filter

--Main> filtriraj [1,2,3,4,6,7,8] (\x -> x `mod` 2 == 0)
--[2,4,6,8] 

sazmi :: [a]->(a->b->b)->b->b
sazmi [] _ e = e
sazmi (h:t) f e = f h (sazmi t f e)

--ugradjene funkcije foldl i foldr 

--Main> sazmi [1,2,3,4] (\x y-> x+y) 0
--10

--Main> sazmi [[1,2,4],[5,6],[]] (++) []
--[1,2,4,5,6]

--obrtanje liste
--Main> foldr (\x y-> y ++ [x]) [] [1,2,3,4,5]
--[5,4,3,2,1]

--Main> foldr (\x y-> if x<y then x else y) (maxBound::Int) --[1,2,3,4,5]
--1

--z1
--Main> filter (\x -> [y | y<-[1..x],x `mod` y==0]/=[1,x]) [1..100]
--[1,4,6,8,9,10,12,14,15,16,18,20,21,22,24,25,26,27,28,30,32,33,34,35--,36,38,39,40,42,44,45,46,48,49,50,51,52,54,55,56,57,58,60,62,63,64
--,65,66,68,69,70,72,74,75,76,77,78,80,81,82,84,85,86,87,88,90,91,92,--93,94,95,96,98,99,100]

--z2
--Main> map (\x-> x++[(foldr (+) 0 x)]) [[1,2,3],[4,5],[],[6]]
--[[1,2,3,6],[4,5,9],[0],[6,6]]

--z3
-- vec uradjen

--z4
--Main> foldr (\x y-> if y==[] then [x] else if x==(head y) then y --else x:y) [] [1,1,2,3,3,3,2,2,5]
--[1,2,3,2,5]

--z5
--Main> foldr (\x y -> ((fst x):(fst y),(snd x):(snd y))) ([],[]) [(1,2),(3,4),(5,6)]
--([1,3,5],[2,4,6])