Problem 91
http://projecteuler.net/index.php?section=problems&id=91
三角形だと思ったら、直角三角形だった。
import Data.Array import Data.List p091 m = length [(a,b)|a<-area,b<-takeWhile(<a)area,not (line a b),isR a b] where area = range((0,0),(m,m)) line (x,y) (u,v) = x*v==y*u isR (x,y) (u,v) = norm(x,y)+norm(u,v)-norm(x-u,y-v)==0|| norm(x,y)-norm(u,v)+norm(x-u,y-v)==0|| norm(x,y)-norm(u,v)-norm(x-u,y-v)==0 norm (x,y) = x*x+y*y main = print.p091$50