Project Euler - Problem 5

so easy.

	import System.IO
	main = do
	putStrLn $ show $ foldr lcm 1 [1..20]

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Project Euler - Problem 4

I thought a little bit cuz I'm new to Haskell.

	import System.IO
	main = do
	putStrLn $ biggest "0" [ show (a*b) | a <- [100..999], b <- [100..999], isPalindromicNum (show (a*b))]
	isPalindromicNum [] = True
	isPalindromicNum (_:[]) = True
	isPalindromicNum (x:xs) | x == last xs = isPalindromicNum (init xs)
	| otherwise = False
	biggest m [] = m
	biggest m (x:xs) | x' > m' = biggest x xs
	| otherwise = biggest m xs
	where x' = (read x)::Integer
	m' = (read m)::Integer

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Project Euler - Problem 3

I solved this in standard and boring way.

	import System.IO
	main = do
	putStrLn $ show $ last $ filter ((== 0) . (mod 600851475143)) (takeWhile (< (truncate (sqrt 600851475143))) prime)
	prime = 2:f [3] [3,5..]
	where f (x:xs) ys = let (ps, qs) = span (< x^2) ys
	in ps ++ f (xs ++ ps) [z | z <- qs, z `mod` x /= 0]

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Project Euler - Problem 2

This was also so easy :)

	import System.IO
	main = do
	putStrLn $ show $ sum $ filter even $ takeWhile ((>) 4000000) fib
	fib = 1:2:[ a+b | (a,b) <- zip fib (tail fib)]

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Project Euler - Problem 1

that was so easy :)

	import System.IO
	main = do
	putStrLn $ show $ sum $ filter judge [1..999]
	judge a | a `mod` 3 == 0 || a `mod` 5 == 0 = True
	| otherwise = False

view raw gistfile1.hs hosted with ❤ by GitHub

Google in Ascii Art

Just type "AA" in text box of Google search.

you'll have fun with Google Logo!

I didn't know this, but I could get this with Google sidewiki, an extension of Google chrome.

thanks for Google sidewiki !

It will tell you very useful or interesting or funny wisdom :-)

Awesome! > Wolfram Alpha

Wolfram Alpha is awesome!

It really help me do my homework :-)

if you want to know the integrate x^2 by x from 10 to 20, just type

integrate 10 to 20, x^2

and press return key, wolfram alpha tell you the result.