- 追加された行はこの色です。
- 削除された行はこの色です。
変な処理があれば修正してください。
*ループ1 [#a13940a0]
[[問題文>練習問題#eb2c4338]]
times 0 action = return ()
times n action = action >> times (n-1) action
main = do
5 `times` putStrLn "Hello World!"
*ループ2 [#ob0d5bdb]
[[問題文>練習問題#eb2c4338]]
import System.Environment
times 0 action = return ()
times n action = action >> times (n-1) action
main = do
x <- getArgs
(read (x !! 0)) `times` putStrLn "Hello World!"
*FizzBuzz [#f4c6d1f7]
[[問題文>練習問題#t52e5a48]]
main = do
mapM_ putStrLn (map fizzBuzz [1..100])
fizzBuzz :: Integer -> String
fizzBuzz n
| n `mod` 15 == 0 = "FizzBuzz"
| n `mod` 5 == 0 = "Buzz"
| n `mod` 3 == 0 = "Fizz"
| otherwise = show n
*素数列挙 [#ld4986f8]
[[問題文>練習問題#o8db2119]]
primesTo m = 2 : sieve [3, 5..m] where
sieve [] = []
sieve (p:xs) = p : sieve (xs `minus` [p*p, p*p+2*p..m])
minus (x:xs) (y:ys) = case (compare x y) of
LT -> x : minus xs (y:ys)
EQ -> minus xs ys
GT -> minus (x:xs) ys
minus xs _ = xs
main = do
print $ primesTo (floor 1e6)
*うるう年判定 [#rc63b4a5]
[[問題文>練習問題#i0d67516]]
isleap :: Integer -> Bool
isleap y
| y `mod` 400 == 0 = True
| y `mod` 100 == 0 = False
| y `mod` 4 == 0 = True
| otherwise = False
main = do
putStrLn "西暦を入力してください"
x <- getLine
putStrLn (x ++ "年はうるう年" ++ if isleap(read(x)) then "です" else "ではありません" )
*フィボナッチ数列 [#mf294cb0]
[[問題文>練習問題#p59f794f]]
import System.Environment
fibo = 0 : 1 : zipWith (+) fibo (tail fibo)
main = do
x <- getArgs
putStrLn (show (fibo !! read (x !! 0)))
*累乗1 [#b0e3fd20]
[[問題文>練習問題#x6e30de3]]
pow :: Integer -> Integer -> Integer
pow _ 0 = 1
pow 0 _ = 0
pow a b = a * pow a (b-1)
main = do
putStrLn (show (pow 2 10))
*累乗2 [#w1eaeb0e]
[[問題文>練習問題#x6e30de3]]
pow :: Integer -> Integer -> Integer
pow 0 _ = 0
pow _ 0 = 1
pow a b = pow' 1 a b
where
pow' x a 0 = x
pow' x a b
| even b = pow' x (a*a) (div b 2)
| otherwise = pow' (x*a) a (b-1)
main = do
putStrLn (show (pow 2 1000007))
*クイックソート [#w101147e]
[[問題文>練習問題(アルゴリズム編)#q8e0119e]]
quicksort :: (Ord a) => [a] -> [a]
quicksort [] = []
quicksort (x:xs) =
let smallerSorted = quicksort[a | a<-xs, a <= x]
biggerSorted = quicksort[a | a<-xs, a > x]
in smallerSorted ++ [x] ++ biggerSorted
main :: IO()
main = print $ quicksort [5, 7, 9, 2, 1, 3, 8, 4, 6, 0]