22 files changed, 436 insertions, 0 deletions
diff --git a/clojure/p1.clj b/clojure/p1.clj
new file mode 100644
index 0000000..2f66db1
--- /dev/null
+++ b/clojure/p1.clj
@@ -0,0 +1,8 @@
+(defn multiplo-3-o-5? [n]
+  (or
+    (zero? (mod n 3))
+    (zero? (mod n 5))))
+
+(let [lista     (range 2 1000)
+      lista_mul (filter multiplo-3-o-5? lista)]
+  (println (apply + lista_mul)))
diff --git a/clojure/p3.clj b/clojure/p3.clj
new file mode 100644
index 0000000..39ae510
--- /dev/null
+++ b/clojure/p3.clj
@@ -0,0 +1,9 @@
+(loop [number 600851475143
+       divisors ()]
+  (if (> number 1)
+    (let [div (or (some #(if (zero? (mod number %)) % false)
+                    (cons 2 (range 3 (/ number 2) 2)))
+                  number)]
+      (recur (/ number div)
+             (cons div divisors)))
+    (println (apply max divisors))))
diff --git a/clojure/primos.clj b/clojure/primos.clj
new file mode 100644
index 0000000..2dc908e
--- /dev/null
+++ b/clojure/primos.clj
@@ -0,0 +1,29 @@
+(ns primos)
+
+(defn not-divide? [m n]
+  (or
+    (= m n)
+    (not (zero? (mod m n)))))
+
+(defn criba [n]
+  (let [raiz (-> n (Math/sqrt) (Math/ceil) (int))]
+    (loop [lista (cons 2 (range 3 (inc n) 2))
+           elm   3]
+      (if (< elm raiz)
+        (let [nueva_lista (filter (fn [n] (not-divide? n elm)) lista)]
+          (recur nueva_lista
+                 (some #(if (> % elm) % false) nueva_lista)))
+        lista))))
+
+(defn divisores [n]
+  (let [criba-n (criba (/ n 2))]
+    (loop [n-actual n
+           divis    []]
+      (if (> n-actual 1)
+        (let [divisible? (fn [primo] (if (zero? (mod n-actual primo)) primo false))
+              divisor    (or (some divisible? criba-n) n-actual)]
+          (recur (/ n-actual divisor)
+                 (cons divisor divis)))
+        divis))))
+
+;(println (divisores (* 2 128473)))
diff --git a/haskell/clean.sh b/haskell/clean.sh
new file mode 100755
index 0000000..f4f85d9
--- /dev/null
+++ b/haskell/clean.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+rm -f *.hi
+rm -f *.o
+rm -f p{1..400}
diff --git a/haskell/p1.hs b/haskell/p1.hs
new file mode 100644
index 0000000..3241a79
--- /dev/null
+++ b/haskell/p1.hs
@@ -0,0 +1,4 @@
+p1 :: Int
+p1 = sum [x | x <- [1..999], mod x 3 == 0 || mod x 5 == 0]
+
+main = putStrLn $ "Solution: " ++ show p1
diff --git a/haskell/p10.hs b/haskell/p10.hs
new file mode 100644
index 0000000..e7a7c85
--- /dev/null
+++ b/haskell/p10.hs
@@ -0,0 +1,12 @@
+sieve :: Int -> [Int]
+sieve max = sieve_l [2..max] (floor . sqrt . fromIntegral $ max)
+	where
+		sieve_l [n] _ = [n]
+		sieve_l (n:xl) max_sqrt
+			| n > max_sqrt	= n:xl
+			| otherwise		= n : sieve_l (filter ((/= 0).(`mod` n)) xl) max_sqrt
+
+p10 :: Int
+p10 = sum $ sieve 2000000
+
+main = putStrLn $ "Solution: " ++ show p10
diff --git a/haskell/p11.hs b/haskell/p11.hs
new file mode 100644
index 0000000..b1c0a58
--- /dev/null
+++ b/haskell/p11.hs
@@ -0,0 +1,122 @@
+-- Soluciones alternativas; estudiar a conciencia
+--
+-- import List
+--
+-- grid = ...
+--
+-- myMaximum [] = 0
+-- myMaximum xs = maximum xs
+--
+-- takeBy n = filter ((n==) . length) . map (take n) . tails
+--
+-- maxBy n = myMaximum . map product . takeBy n
+--
+-- maxInRows n = maximum . map (maxBy n)
+--
+-- maxInCols n = maxInRows n . transpose
+--
+-- maxInLR n = maxInRows n . transpose . zipWith drop [0..]
+--
+-- maxInRL n = maxInLR n . map reverse
+--
+-- main = print $ maximum $ map (flip ($ 4) grid) [maxInRows, maxInCols, maxInLR, maxInRL]
+-------------------------------------------------------------------------------------------
+-- import Data.Array
+-- import Data.List
+--
+-- input = unlines $
+--         [ "08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08",
+--           "49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00",
+--           "81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65",
+--           "52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91",
+--           "22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80",
+--           "24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50",
+--           "32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70",
+--           "67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21",
+--           "24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72",
+--           "21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95",
+--           "78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92",
+--           "16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57",
+--           "86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58",
+--           "19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40",
+--           "04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66",
+--           "88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69",
+--           "04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36",
+--           "20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16",
+--           "20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54",
+--           "01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48"]
+--
+-- n = 20
+--
+-- mbounds = ((1,1), (n,n))
+--
+-- matrix :: Array (Int, Int) Int
+-- matrix = listArray mbounds $ map read $ words input
+--
+-- k = 4
+--
+-- -- right, down, right-diag, left-diag
+-- directions = [ (0,1), (1,0), (1,1), (1,-1) ]
+--
+-- move (x,y) (dx,dy) = (x+dx, y+dy)
+--
+-- solution = maximum [ product (takeLine pt dir) |
+--                      pt  <- range mbounds,
+--                      dir <- directions]
+--     where takeLine pt dir = [ matrix!pt' |
+--                               pt' <- take k $ iterate (move dir) pt,
+--                               inRange mbounds pt' ]
+
+import Data.List (transpose)
+
+grid :: [[Int]]
+grid =
+	[[08, 02, 22, 97, 38, 15, 00, 40, 00, 75, 04, 05, 07, 78, 52, 12, 50, 77, 91, 08]
+	,[49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 04, 56, 62, 00]
+	,[81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 03, 49, 13, 36, 65]
+	,[52, 70, 95, 23, 04, 60, 11, 42, 69, 24, 68, 56, 01, 32, 56, 71, 37, 02, 36, 91]
+	,[22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80]
+	,[24, 47, 32, 60, 99, 03, 45, 02, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50]
+	,[32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70]
+	,[67, 26, 20, 68, 02, 62, 12, 20, 95, 63, 94, 39, 63, 08, 40, 91, 66, 49, 94, 21]
+	,[24, 55, 58, 05, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72]
+	,[21, 36, 23, 09, 75, 00, 76, 44, 20, 45, 35, 14, 00, 61, 33, 97, 34, 31, 33, 95]
+	,[78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 03, 80, 04, 62, 16, 14, 09, 53, 56, 92]
+	,[16, 39, 05, 42, 96, 35, 31, 47, 55, 58, 88, 24, 00, 17, 54, 24, 36, 29, 85, 57]
+	,[86, 56, 00, 48, 35, 71, 89, 07, 05, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58]
+	,[19, 80, 81, 68, 05, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 04, 89, 55, 40]
+	,[04, 52, 08, 83, 97, 35, 99, 16, 07, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66]
+	,[88, 36, 68, 87, 57, 62, 20, 72, 03, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69]
+	,[04, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 08, 46, 29, 32, 40, 62, 76, 36]
+	,[20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 04, 36, 16]
+	,[20, 73, 35, 29, 78, 31, 90, 01, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 05, 54]
+	,[01, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 01, 89, 19, 67, 48]]
+
+max4 :: [Int] -> Int
+max4 v
+	| (length v) < 4	= 0
+	| otherwise			= maximum [product $ take 4 v, max4 $ tail v]
+
+horizontal :: [[Int]] -> Int
+horizontal = horizontal'
+	where
+		horizontal' :: [[Int]] -> Int
+		horizontal' [] = 0
+		horizontal' (v:m) = maximum [(max4 v), (horizontal' m)]
+
+vertical :: [[Int]] -> Int
+vertical = horizontal . transpose
+
+diagonal :: [[Int]] -> Int
+diagonal m = maximum (map (max4 . diag) [0..(len-1)])
+	where
+		diag n = [grid !! x !! y | x <- [0..n], y <- [0..n], x+y == n]
+		len = length grid
+
+diagonal_back :: [[Int]] -> Int
+diagonal_back = diagonal . (map reverse)
+
+p11 :: Int
+p11 = maximum $ [horizontal grid, vertical grid, diagonal grid, diagonal_back grid]
+
+main = putStrLn $ "Solution: " ++ show p11
diff --git a/haskell/p13.hs b/haskell/p13.hs
new file mode 100644
index 0000000..b290a32
--- /dev/null
+++ b/haskell/p13.hs
@@ -0,0 +1,104 @@
+p13 :: String
+p13 = take 10 $ show $
+	sum [ 37107287533902102798797998220837590246510135740250
+	, 46376937677490009712648124896970078050417018260538
+	, 74324986199524741059474233309513058123726617309629
+	, 91942213363574161572522430563301811072406154908250
+	, 23067588207539346171171980310421047513778063246676
+	, 89261670696623633820136378418383684178734361726757
+	, 28112879812849979408065481931592621691275889832738
+	, 44274228917432520321923589422876796487670272189318
+	, 47451445736001306439091167216856844588711603153276
+	, 70386486105843025439939619828917593665686757934951
+	, 62176457141856560629502157223196586755079324193331
+	, 64906352462741904929101432445813822663347944758178
+	, 92575867718337217661963751590579239728245598838407
+	, 58203565325359399008402633568948830189458628227828
+	, 80181199384826282014278194139940567587151170094390
+	, 35398664372827112653829987240784473053190104293586
+	, 86515506006295864861532075273371959191420517255829
+	, 71693888707715466499115593487603532921714970056938
+	, 54370070576826684624621495650076471787294438377604
+	, 53282654108756828443191190634694037855217779295145
+	, 36123272525000296071075082563815656710885258350721
+	, 45876576172410976447339110607218265236877223636045
+	, 17423706905851860660448207621209813287860733969412
+	, 81142660418086830619328460811191061556940512689692
+	, 51934325451728388641918047049293215058642563049483
+	, 62467221648435076201727918039944693004732956340691
+	, 15732444386908125794514089057706229429197107928209
+	, 55037687525678773091862540744969844508330393682126
+	, 18336384825330154686196124348767681297534375946515
+	, 80386287592878490201521685554828717201219257766954
+	, 78182833757993103614740356856449095527097864797581
+	, 16726320100436897842553539920931837441497806860984
+	, 48403098129077791799088218795327364475675590848030
+	, 87086987551392711854517078544161852424320693150332
+	, 59959406895756536782107074926966537676326235447210
+	, 69793950679652694742597709739166693763042633987085
+	, 41052684708299085211399427365734116182760315001271
+	, 65378607361501080857009149939512557028198746004375
+	, 35829035317434717326932123578154982629742552737307
+	, 94953759765105305946966067683156574377167401875275
+	, 88902802571733229619176668713819931811048770190271
+	, 25267680276078003013678680992525463401061632866526
+	, 36270218540497705585629946580636237993140746255962
+	, 24074486908231174977792365466257246923322810917141
+	, 91430288197103288597806669760892938638285025333403
+	, 34413065578016127815921815005561868836468420090470
+	, 23053081172816430487623791969842487255036638784583
+	, 11487696932154902810424020138335124462181441773470
+	, 63783299490636259666498587618221225225512486764533
+	, 67720186971698544312419572409913959008952310058822
+	, 95548255300263520781532296796249481641953868218774
+	, 76085327132285723110424803456124867697064507995236
+	, 37774242535411291684276865538926205024910326572967
+	, 23701913275725675285653248258265463092207058596522
+	, 29798860272258331913126375147341994889534765745501
+	, 18495701454879288984856827726077713721403798879715
+	, 38298203783031473527721580348144513491373226651381
+	, 34829543829199918180278916522431027392251122869539
+	, 40957953066405232632538044100059654939159879593635
+	, 29746152185502371307642255121183693803580388584903
+	, 41698116222072977186158236678424689157993532961922
+	, 62467957194401269043877107275048102390895523597457
+	, 23189706772547915061505504953922979530901129967519
+	, 86188088225875314529584099251203829009407770775672
+	, 11306739708304724483816533873502340845647058077308
+	, 82959174767140363198008187129011875491310547126581
+	, 97623331044818386269515456334926366572897563400500
+	, 42846280183517070527831839425882145521227251250327
+	, 55121603546981200581762165212827652751691296897789
+	, 32238195734329339946437501907836945765883352399886
+	, 75506164965184775180738168837861091527357929701337
+	, 62177842752192623401942399639168044983993173312731
+	, 32924185707147349566916674687634660915035914677504
+	, 99518671430235219628894890102423325116913619626622
+	, 73267460800591547471830798392868535206946944540724
+	, 76841822524674417161514036427982273348055556214818
+	, 97142617910342598647204516893989422179826088076852
+	, 87783646182799346313767754307809363333018982642090
+	, 10848802521674670883215120185883543223812876952786
+	, 71329612474782464538636993009049310363619763878039
+	, 62184073572399794223406235393808339651327408011116
+	, 66627891981488087797941876876144230030984490851411
+	, 60661826293682836764744779239180335110989069790714
+	, 85786944089552990653640447425576083659976645795096
+	, 66024396409905389607120198219976047599490197230297
+	, 64913982680032973156037120041377903785566085089252
+	, 16730939319872750275468906903707539413042652315011
+	, 94809377245048795150954100921645863754710598436791
+	, 78639167021187492431995700641917969777599028300699
+	, 15368713711936614952811305876380278410754449733078
+	, 40789923115535562561142322423255033685442488917353
+	, 44889911501440648020369068063960672322193204149535
+	, 41503128880339536053299340368006977710650566631954
+	, 81234880673210146739058568557934581403627822703280
+	, 82616570773948327592232845941706525094512325230608
+	, 22918802058777319719839450180888072429661980811197
+	, 77158542502016545090413245809786882778948721859617
+	, 72107838435069186155435662884062257473692284509516
+	, 20849603980134001723930671666823555245252804609722
+	, 53503534226472524250874054075591789781264330331690 ]
+
+main = putStrLn $ "Solution: " ++ p13
diff --git a/haskell/p14.hs b/haskell/p14.hs
new file mode 100644
index 0000000..fae33f8
--- /dev/null
+++ b/haskell/p14.hs
@@ -0,0 +1,17 @@
+collatz :: Int -> [Int]
+collatz 1 = [1]
+collatz n
+	| mod n 2 == 0	= n : collatz (div n 2)
+	| mod n 2 == 1	= n : collatz (3*n + 1)
+
+p14 :: Int
+p14 = p14' 999999 0 0
+	where
+		p14' 0 maxnum _ = maxnum
+		p14' n maxnum maxlen =
+			let len = length (collatz n)
+			in if len > maxlen
+				then p14' (n-1) n len
+				else p14' (n-1) maxnum maxlen
+
+main = putStrLn $ "Solution: " ++ show p14
diff --git a/haskell/p15.hs b/haskell/p15.hs
new file mode 100644
index 0000000..41b93cf
--- /dev/null
+++ b/haskell/p15.hs
@@ -0,0 +1,16 @@
+grid_bad 0 _ = 1
+grid_bad r c
+	| r == c	= 2 * (grid_bad (r-1) c)
+	| otherwise	= (grid_bad (r-1) c) + (grid_bad r (c-1))
+
+grid 0 _ = 1
+grid 1 n = n + 1
+grid 2 n = sum [1..n] + n + 1
+grid r c
+	| r == c	= 2 * (grid (r-1) c)
+	| otherwise	= (grid (r-1) c) + (grid r (c-1))
+
+p15 :: Int -> Int
+p15 n = grid n n
+
+main = putStrLn $ "Solution: " ++ show (p15 20)
diff --git a/haskell/p16.hs b/haskell/p16.hs
new file mode 100644
index 0000000..89de59f
--- /dev/null
+++ b/haskell/p16.hs
@@ -0,0 +1,6 @@
+import Data.Char (digitToInt)
+
+p16 :: Int
+p16 = sum (map digitToInt (show (2^1000)))
+
+main = putStrLn $ "Solution: " ++ show p16
diff --git a/haskell/p2.hs b/haskell/p2.hs
new file mode 100644
index 0000000..1d9d769
--- /dev/null
+++ b/haskell/p2.hs
@@ -0,0 +1,8 @@
+fibs :: [Int]
+fibs = list
+	where list = 0 : 1 : zipWith (+) list (tail list)
+
+p2 :: Int
+p2 = sum [x | x <- takeWhile (< 4000000) fibs, mod x 2 == 0]
+
+main = putStrLn $ "Solution: " ++ show p2
diff --git a/haskell/p20.hs b/haskell/p20.hs
new file mode 100644
index 0000000..d9468e8
--- /dev/null
+++ b/haskell/p20.hs
@@ -0,0 +1,6 @@
+import Data.Char (digitToInt)
+
+p20 :: Int
+p20 = sum (map digitToInt (show (product [1..100])))
+
+main = putStrLn $ "Solution: " ++ show p20
diff --git a/haskell/p3.hs b/haskell/p3.hs
new file mode 100644
index 0000000..f50c2de
--- /dev/null
+++ b/haskell/p3.hs
@@ -0,0 +1,9 @@
+p3 :: Integer
+p3 = maximum $ factors 600851475143 []
+	where
+		factors :: Integer -> [Integer] -> [Integer]
+		factors 1 l = l
+		factors n l = factors (div n divisor) (divisor:l)
+			where divisor = head $ filter (\x -> mod n x == 0) [2..]
+
+main = putStrLn $ "Solution: " ++ show p3
diff --git a/haskell/p377.hs b/haskell/p377.hs
new file mode 100644
index 0000000..f511046
--- /dev/null
+++ b/haskell/p377.hs
@@ -0,0 +1,12 @@
+import Data.Char
+
+f :: Int -> Integer
+f n = sum [x | x <- [1..10^n], nozero x, sumn x n]
+	where
+		nozero x = notElem '0' (show x)
+		sumn x n = sum (map digitToInt (show x)) == n
+
+p377 :: String
+p377 = reverse . (take 9) . reverse . show $ sum [f 13^i | i <- [1..17]]
+
+main = putStrLn $ "Solution: " ++ p377
diff --git a/haskell/p4.hs b/haskell/p4.hs
new file mode 100644
index 0000000..2670bd5
--- /dev/null
+++ b/haskell/p4.hs
@@ -0,0 +1,7 @@
+palindrome :: (Integral a) => a -> Bool
+palindrome n = let ns = show n in ns == reverse ns
+
+p4 :: Int
+p4 = maximum $ filter palindrome [x*y | x <- [100..999], y <- [100..999]]
+
+main = putStrLn $ "Solution: " ++ show p4
diff --git a/haskell/p5.hs b/haskell/p5.hs
new file mode 100644
index 0000000..ccee7fe
--- /dev/null
+++ b/haskell/p5.hs
@@ -0,0 +1,8 @@
+p5' :: Integer
+p5' = foldl lcm 1 [1..20]
+
+p5 :: Integer
+p5 = head $ filter cond [1..]
+	where cond n = null [x | x <- [2..20], mod n x /= 0]
+
+main = putStrLn $ "Solution: " ++ show p5
diff --git a/haskell/p6.hs b/haskell/p6.hs
new file mode 100644
index 0000000..86f509d
--- /dev/null
+++ b/haskell/p6.hs
@@ -0,0 +1,4 @@
+p6 :: Int
+p6 = (sum [1..100])^2 - foldl (\a x -> x^2 + a) 0 [1..100]
+
+main = putStrLn $ "Solution: " ++ show p6
diff --git a/haskell/p7.hs b/haskell/p7.hs
new file mode 100644
index 0000000..fe91b10
--- /dev/null
+++ b/haskell/p7.hs
@@ -0,0 +1,6 @@
+sieve (x:xs) = x : sieve (filter ((/= 0) . (`mod` x)) xs)
+
+p7 :: Int
+p7 = sieve [2..] !! 10000
+
+main = putStrLn $ "Solution: " ++ show p7
diff --git a/haskell/p8.hs b/haskell/p8.hs
new file mode 100644
index 0000000..61f0f4c
--- /dev/null
+++ b/haskell/p8.hs
@@ -0,0 +1,34 @@
+import Data.Char (digitToInt)
+
+p8 :: Int
+p8 = greatest5 "\
+				\73167176531330624919225119674426574742355349194934\
+				\96983520312774506326239578318016984801869478851843\
+				\85861560789112949495459501737958331952853208805511\
+				\12540698747158523863050715693290963295227443043557\
+				\66896648950445244523161731856403098711121722383113\
+				\62229893423380308135336276614282806444486645238749\
+				\30358907296290491560440772390713810515859307960866\
+				\70172427121883998797908792274921901699720888093776\
+				\65727333001053367881220235421809751254540594752243\
+				\52584907711670556013604839586446706324415722155397\
+				\53697817977846174064955149290862569321978468622482\
+				\83972241375657056057490261407972968652414535100474\
+				\82166370484403199890008895243450658541227588666881\
+				\16427171479924442928230863465674813919123162824586\
+				\17866458359124566529476545682848912883142607690042\
+				\24219022671055626321111109370544217506941658960408\
+				\07198403850962455444362981230987879927244284909188\
+				\84580156166097919133875499200524063689912560717606\
+				\05886116467109405077541002256983155200055935729725\
+				\71636269561882670428252483600823257530420752963450" 0
+	where
+		greatest5 (_:_:_:[_]) max = max
+		greatest5 l max =
+			let first5 = product (map digitToInt (take 5 l))
+			in if first5 > max
+				then greatest5 (tail l) first5
+				else greatest5 (tail l) max
+
+
+main = putStrLn $ "Solution: " ++ show p8
diff --git a/haskell/p9.hs b/haskell/p9.hs
new file mode 100644
index 0000000..f06f441
--- /dev/null
+++ b/haskell/p9.hs
@@ -0,0 +1,7 @@
+triplet :: (Integral a) => a -> a -> a -> Bool
+triplet a b c = a^2 + b^2 == c^2
+
+p9 :: Int
+p9 = head [x*y*z | x <- [2..333], y <- [2..1000], z <- [333..1000], triplet x y z, x+y+z == 1000]
+
+main = putStrLn $ "Solution: " ++ show p9
diff --git a/haskell/template.hs b/haskell/template.hs
new file mode 100644
index 0000000..a72d31e
--- /dev/null
+++ b/haskell/template.hs
@@ -0,0 +1,4 @@
+p4 :: Int
+p4 =
+
+main = putStrLn $ "Solution: " ++ show p4