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Eban numbers: Difference between revisions
m
→{{header|Haskell}}
Line 657:
{{trans|Julia}}
<lang haskell>{-# LANGUAGE NumericUnderscores #-}
import Data.List (find)
import Text.Printf (printf)
isEban :: Int -> Bool
Line 665 ⟶ 667:
(t, r3) = r2 `quotRem` (10 ^ 3)
z = b : map (\x -> if x >= 30 && x <= 66 then x `mod` 10 else x) [m, t, r3]
ebans :: [Int] -> [(Int, Int)]
ebans = go
where
ebanCount = zip [1..] (filter isEban [1..])
go [] = []
go (x:xs) = case find (\(_, e) -> x < e) ebanCount of
Just (c, e) -> (x, pred c) : go xs
Nothing -> go xs
main :: IO ()
main = do
where
ebanCounts = ebans [ 10_000
, 100_000
t = show . length . filter isEban</lang>▼
, 1_000_000
, 10_000_000
, 100_000_000
, 1_000_000_000 ]
{{out}}
<pre>
eban numbers up to and including
[2,4,6,30,32,34,36,40,42,44,46,50,52,54,56,60,62,64,66]
eban numbers between
[2000,2002,2004,2006,2030,2032,2034,2036,2040,2042,2044,2046,2050,2052,2054,2056,2060,2062,2064,2066,4000]
eban numbers up and including 10000:
eban numbers up and including 100000:
eban numbers up and including 1000000:
eban numbers up and including
eban numbers up and including 100000000: 7999
eban numbers up and including 1000000000: 7999
</pre>
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