Add problem11

Author: adamhp

problem003/problem3.hs

@@ -7,7 +7,9 @@ main :: IO ()
 
 -- Super lazy isPrime
 isPrime :: Int -> Bool
-isPrime x 
+isPrime x
+  | x == 1 = False
+  | x == 2 = True
   | even x = False
   | otherwise = (<3) $ length $ filter (== 0) $ map (mod x) [1..x]
 

problem007/problem7.hs

@@ -22,6 +22,8 @@ time a = do
 
 prime :: Int -> Bool
 prime n 
+  | n == 1 = False
+  | n == 2 = True
   | even n = False
   | otherwise = Nothing == (find (==0) $ map (mod n) [(n-2),(n-4)..3])
 

problem009/problem9

@@ -1,5 +1,5 @@
 import Data.List
-import Data.Maybe
+import Data.Array.Unboxed
 import Text.Printf
 import Control.Exception
 import System.CPUTime
@@ -19,19 +19,23 @@ time a = do
 The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.
 
 Find the sum of all the primes below two million.
+
+TODO: Optimize
 -}
 --
-prime :: Int -> Bool
-prime n 
-  | even n = False
-  | otherwise = Nothing == (find (==0) $ map (mod n) [(n-2),(n-4)..3])
+isprime :: (Integral i) => i -> Bool
+isprime n = isprime_ n primes
+  where isprime_ n (p:ps)
+          | p*p > n        = True
+          | n `mod` p == 0 = False
+          | otherwise      = isprime_ n ps
+
+primes :: (Integral i) => [i]
+primes = 2 : filter isprime [3,5..]
+
 
-sum' :: [Integer] -> Int
-sum' = foldl (+) 0
 -- 
--- TODO Time solution and add produt of resulting tuple below
--- find (isTriplet) [(x,y,z) | x <- [1..1000], y <- [x..1000], z <- [y..1000], x+y+z==1000]
-solution = putStrLn $ show $ sum' [x.. | x <- prime x]
+solution = putStrLn $ show $ foldl (+) 0 $ takeWhile (<2000000) primes
 
 main = do
   putStrLn "Starting..."

problem010/problem10

@@ -0,0 +1,20 @@
+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

problem010/problem10.hs

@@ -0,0 +1,87 @@
+{-
+In the 20×20 grid below, four numbers along a diagonal line have been marked in 
+red.
+
+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
+
+The product of these numbers is 26 × 63 × 78 × 14 = 1788696.
+
+What is the greatest product of four adjacent numbers in the same direction 
+(up, down, left, right, or diagonally) in the 20×20 grid?
+-}
+
+-- Get rows
+-- Get columns
+-- Get windowed rows, columns, diagonals
+-- Calculate product, take maximum
+
+import Data.List
+import Data.Array
+import Text.Printf
+import Control.Exception
+import System.CPUTime
+import System.Environment
+
+main :: IO ()
+time :: IO t -> IO t
+time a = do
+    start <- getCPUTime
+    v <- a
+    end   <- getCPUTime
+    let diff = (fromIntegral (end - start)) / (10^12)
+    printf "Computation time: %0.3f sec\n" (diff :: Double)
+    return v
+
+-- 
+window :: Int -> [Int] -> [[Int]]
+window n list = 
+  case list of 
+    [] -> []
+    x:xs -> 
+      if length list >= n 
+      then ( x : (take (n-1) xs) ) : window n xs
+      else window n xs
+
+hasZero :: [Int] -> Bool
+hasZero [] = True
+hasZero (x:xs) = if x == 0 then True else hasZero xs
+-- 
+
+-- solution :: Integer -> IO ()
+-- solution n = putStrLn $ window n
+-- getRows = (map (map read) $ map words $ lines contents :: [[Int]])
+
+main = do
+  contents <- readFile "./number.txt"
+  let rows = map (map read) $ map words $ lines contents :: [[Int]]
+  let cols = transpose rows
+  let diags = filter hasZero $ filter (((==4) . length)) $ concatMap (transpose . zipWith drop [0..3]) (tails rows)
+  let diags2 = filter hasZero $ filter ((==4) . length) $ concatMap (transpose . zipWith drop [0..3]) (tails $ reverse rows)
+  let mappedRows = filter hasZero $ concatMap (window 4) rows
+  let mappedCols = filter hasZero $ concatMap (window 4) cols
+  let all = diags ++ diags2 ++ mappedRows ++ mappedCols
+  let solution = maximum $ map product all
+  putStrLn "Starting..."
+  putStrLn $ show solution
+  -- time $ solution number
+  putStrLn "Done."
+