From 9a65938232d1fa9e1afe9a6eb2de48d25ff738a6 Mon Sep 17 00:00:00 2001 From: Charles Date: Sat, 17 Aug 2019 20:39:03 +0200 Subject: haskell problem 22, 24, 25, 29, 39, 40, 45, 53, 59 --- haskell/040-champernowne_s_constant.hs | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 haskell/040-champernowne_s_constant.hs (limited to 'haskell/040-champernowne_s_constant.hs') 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] -- cgit