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@@ -0,0 +1,26 @@
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+{-
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+A Pythagorean triplet is a set of three natural numbers, a < b < c, for which, a^2 + b^2 = c^2.
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+For example, 3^2 + 4^2 = 9 + 16 = 25 = 5^2.
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+There exists exactly one Pythagorean triplet for which a + b + c = 1000.
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+Find the product abc.
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+-}
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+
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+solution :: Int
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+solution = go' 1 1 1 10
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+ where
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+ target :: Int
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+ target = 1000
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+
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+ is_pit3 :: Int -> Int -> Int -> Bool
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+ is_pit3 a b c = (a*a + b*b) == c*c
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+
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+ go' :: Int -> Int -> Int -> Int -> Int
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+ go' a b c tag
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+ | a == tag = go' 1 (b+1) c tag
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+ | b == tag = go' 1 1 (c+1) tag
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+ | c == tag = go' 1 1 1 (tag*2)
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+ | (is_pit3 a b c) && (a+b+c) == target = a*b*c
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+ | otherwise = go' (a+1) b c tag
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+
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+main :: IO ()
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+main = putStrLn ("Solution: " ++ show solution)
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