Project Euler 解答

Project Euler Problem 085

Project Euler Problem 085

import Control.Monad
import Data.List
import Data.Ord

-- 指定された幅、高さの長方形の個数
num :: (Enum a, Num a) => a -> a -> a
num ww hh = sum [wl*hl| w<-[1..ww],h<-[1..hh],let wl=ww-w+1,let hl=hh-h+1]
anslist :: [(Integer, (Integer, Integer))]
anslist = [(num i j,(i,j)) | i<-[1..2011],j<-dropWhile (\x -> num i x < 1975000) $ takeWhile (\x -> num i x < 2025000) [1..]]
-- (面積,長方形の個数,(縦,横))
ans :: (Integer, Integer, (Integer, Integer))
ans = (i*j,v,(i,j)) where  (v,(i,j)) = head $ sortBy (comparing (abs.(subtract 2000000).fst)) $ anslist

ans1 = let (a,_,_)= asn in a
-- 2772
main :: IO ()
main = print ans1

since 2013