June 2018 Update

Task/Zebra-puzzle/Julia/zebra-puzzle.julia

@@ -0,0 +1,51 @@
+function make(str, test = (_) -> true)
+  collect( filter(test, permutations(split(str))) )
+end
+
+men = make("danish english german norwegian swedish",
+           x -> "norwegian" == x[1])
+
+drinks = make("beer coffee milk tea water", x -> "milk" == x[3])
+
+colors = make("blue green red white yellow",
+              x -> 1 == findfirst(x, "white") - findfirst(x, "green"))
+
+pets = make("birds cats dog horse zebra")
+
+smokes = make("blend blue-master dunhill pall-mall prince")
+
+function eq(x, xs, y, ys)
+  findfirst(xs, x) == findfirst(ys, y)
+end
+
+function adj(x, xs, y, ys)
+  1 == abs(findfirst(xs, x) - findfirst(ys, y))
+end
+
+for m = men, c = colors
+  if eq("red",c, "english",m) && adj("norwegian",m, "blue",c)
+    for d = drinks
+      if eq("danish",m, "tea",d) && eq("coffee",d,"green",c)
+        for s = smokes
+          if eq("yellow",c,"dunhill",s) &&
+             eq("blue-master",s,"beer",d) &&
+             eq("german",m,"prince",s)
+            for p = pets
+              if eq("birds",p,"pall-mall",s) &&
+                 eq("swedish",m,"dog",p) &&
+                 adj("blend",s,"cats",p) &&
+                 adj("horse",p,"dunhill",s)
+                println("Zebra is owned by ", m[findfirst(p,"zebra")])
+                println("Houses:")
+                for line = mapslices(xs -> join( map(s->rpad(s,12), xs)),
+                                     [p m c d s], 2)
+                  println(line)
+                end
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end