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Diffstat (limited to 'haskell/040-champernowne_s_constant.hs')
| -rw-r--r-- | haskell/040-champernowne_s_constant.hs | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/haskell/040-champernowne_s_constant.hs b/haskell/040-champernowne_s_constant.hs new file mode 100644 index 0000000..59cb1b4 --- /dev/null +++ b/haskell/040-champernowne_s_constant.hs @@ -0,0 +1,22 @@ +-- An irrational decimal fraction is created by concatenating the positive integers: +-- +-- 0.123456789101112131415161718192021... +-- +-- It can be seen that the 12th digit of the fractional part is 1. +-- +-- If dn represents the nth digit of the fractional part, +-- find the value of the following expression. +-- +-- d1 × d10 × d100 × d1000 × d10000 × d100000 × d1000000 + + +-- main = print (1 + sum [9 * 10 ^ i | i <- [0..5]]) +main = do + print (product [champernowne !! (10 ^ i - 1) | i <- [0..6]]) + +champernowne = concat [showNbr n | n <- [1..]] + +showNbr :: Integer -> [Integer] +showNbr x + | x < 10 = [x] + | otherwise = showNbr (x `div` 10) ++ [x `mod` 10] |