maze-src: distances.rb comparison

initial commit of maze game source

comparison

equal deleted inserted replaced

--1:000000000000
+:1eef88068f9f
+#---
+# Excerpted from "Mazes for Programmers",
+# published by The Pragmatic Bookshelf.
+# Copyrights apply to this code. It may not be used to create training material,
+# courses, books, articles, and the like. Contact us if you are in doubt.
+# We make no guarantees that this code is fit for any purpose.
+# Visit http://www.pragmaticprogrammer.com/titles/jbmaze for more book information.
+#---
+class Distances
+def initialize(root)
+@root = root
+@cells = {}
+@cells[@root] = 0
+end
+def [](cell)
+@cells[cell]
+end
+def []=(cell, distance)
+@cells[cell] = distance
+end
+def cells
+@cells.keys
+end
+def path_to(goal)
+current = goal
+breadcrumbs = Distances.new(@root)
+breadcrumbs[current] = @cells[current]
+until current == @root
+current.links.each do |neighbor|
+if @cells[neighbor] < @cells[current]
+breadcrumbs[neighbor] = @cells[neighbor]
+current = neighbor
+break
+end
+end
+end
+breadcrumbs
+end
+def max
+max_distance = 0
+max_cell = @root
+@cells.each do |cell, distance|
+if distance > max_distance
+max_cell = cell
+max_distance = distance
+end
+end
+[max_cell, max_distance]
+end
+end

Mercurial > maze-src