diff --git a/Haskell/p008.hs b/Haskell/p008.hs new file mode 100644 index 0000000..5050e36 --- /dev/null +++ b/Haskell/p008.hs @@ -0,0 +1,56 @@ +-- The four adjacent digits in the 1000-digit number that have the greatest product are 9 × 9 × 8 × 9 = 5832. +-- +-- 73167176531330624919225119674426574742355349194934 +-- 96983520312774506326239578318016984801869478851843 +-- 85861560789112949495459501737958331952853208805511 +-- 12540698747158523863050715693290963295227443043557 +-- 66896648950445244523161731856403098711121722383113 +-- 62229893423380308135336276614282806444486645238749 +-- 30358907296290491560440772390713810515859307960866 +-- 70172427121883998797908792274921901699720888093776 +-- 65727333001053367881220235421809751254540594752243 +-- 52584907711670556013604839586446706324415722155397 +-- 53697817977846174064955149290862569321978468622482 +-- 83972241375657056057490261407972968652414535100474 +-- 82166370484403199890008895243450658541227588666881 +-- 16427171479924442928230863465674813919123162824586 +-- 17866458359124566529476545682848912883142607690042 +-- 24219022671055626321111109370544217506941658960408 +-- 07198403850962455444362981230987879927244284909188 +-- 84580156166097919133875499200524063689912560717606 +-- 05886116467109405077541002256983155200055935729725 +-- 71636269561882670428252483600823257530420752963450 +-- +-- Find the thirteen adjacent digits in the 1000-digit number that have the greatest product. What is the value of this product? + +import Data.Char + +nDigitProduct :: Int -> String -> Int +nDigitProduct n s + | length s < n = -1 + | otherwise = max (product (map digitToInt (take n s))) (nDigitProduct n (tail s)) + +main = do + let s = "73167176531330624919225119674426574742355349194934" + ++ "96983520312774506326239578318016984801869478851843" + ++ "85861560789112949495459501737958331952853208805511" + ++ "12540698747158523863050715693290963295227443043557" + ++ "66896648950445244523161731856403098711121722383113" + ++ "62229893423380308135336276614282806444486645238749" + ++ "30358907296290491560440772390713810515859307960866" + ++ "70172427121883998797908792274921901699720888093776" + ++ "65727333001053367881220235421809751254540594752243" + ++ "52584907711670556013604839586446706324415722155397" + ++ "53697817977846174064955149290862569321978468622482" + ++ "83972241375657056057490261407972968652414535100474" + ++ "82166370484403199890008895243450658541227588666881" + ++ "16427171479924442928230863465674813919123162824586" + ++ "17866458359124566529476545682848912883142607690042" + ++ "24219022671055626321111109370544217506941658960408" + ++ "07198403850962455444362981230987879927244284909188" + ++ "84580156166097919133875499200524063689912560717606" + ++ "05886116467109405077541002256983155200055935729725" + ++ "71636269561882670428252483600823257530420752963450" + result = nDigitProduct 13 s + putStrLn $ "Project Euler, Problem 8\n" + ++ "Answer: " ++ show result diff --git a/Haskell/p015.hs b/Haskell/p015.hs new file mode 100644 index 0000000..cf72be4 --- /dev/null +++ b/Haskell/p015.hs @@ -0,0 +1,11 @@ +-- Starting in the top left corner of a 2×2 grid, and only being able to move to the right and down, there are exactly 6 routes to the bottom right corner +-- How many such routes are there through a 20×20 grid? + +factorial :: (Integral a) => a -> a +factorial 0 = 1 +factorial n = n * factorial (n - 1) + +main = do + let result = factorial 40 `div` factorial 20 ^ 2 + putStrLn $ "Project Euler, Problem 15\n" + ++ "Answer: " ++ show result