小编pvl*_*pvl的帖子

我有一个文件(points.txt)定义了一些笛卡尔坐标:

A 1.0 2.2
B 2.1 3.0
C 3.5 4.0
D 4.0 5.0

我有第二个文件(routes.txt),其路由根据points.txt中的点定义.

route1 ACDB
route2 ABC

我需要找到每条路线的长度.到目前为止,我计算了两点之间的距离,如下所示:

type Point = (String, Float, Float)

distance_points :: IO ()
distance_points = do s <- readFile "pontos.txt"
                      putStr "Fom: "
                      p1 <- getLine
                      putStr "To: "
                      p2 <- getLine
                      print ( distance (search_point p1 (map words (lines s))) (search_point p2 (map words (lines s))))

search_point :: String -> [[String]] -> Point
search_point pt ([p,c1,c2]:xs) = if pt == p then (p, …