scalaで迷路(穴掘り法)

Digging.scala

import scala.util.Random

object Digging {
	def printMaze(m:Map[(Int,Int), String])(implicit size:(Int,Int)) = {
		val w = size._1
		val h = size._2
		for(j <- 0 until h)
		{
			for(i <- 0 until w){
				m.get((i,j)) match {
					case Some(s) => print(s)
					case None => print(" ")
				}
			}
			println("")
		}
	}

	def canDig(src:Map[(Int,Int),String])(target:(Int,Int), from:(Int,Int))(implicit size:(Int,Int)) = {
		if(!src.contains(target)) false
		else {
			val dx = target._1 - from._1
			val dy = target._2 - from._2
			var suggest = aroundPoint(target)(size) filter(s => {
				src.get(s) match {
					case Some(n) => true
					case None => false
				}
			})
			suggest.length == 3
		}
	}

	def intersect[T1,T2](m1:Map[T1,T2],m2:Map[T1,T2]) : Map[T1,T2] = {
		(m1.toList intersect m2.toList).toMap
	} 

	def dig(pos:(Int,Int), bsrc:Map[(Int,Int),String])(implicit size:(Int,Int)) : Map[(Int,Int),String] = {
		var src = bsrc
		src -= pos

		var arounds = (new Random).shuffle(aroundPoint(pos)(size))
		while(!arounds.isEmpty){
			if(canDig(src)(arounds.head,pos)(size)) src = intersect(src,dig(arounds.head,src)(size))
			arounds = arounds.tail
		}
		src
	}

	def fill(implicit size:(Int,Int), wall:String) = (for(i <- 0 until size._1 ; j <- 0 until size._2) yield ((i,j) -> wall)).toMap
	
	def main(args:Array[String]) = {
		implicit val w = 40
		implicit val h = 20
		implicit val size = (w,h)
		implicit val wall = "#"

		val r = new Random
		val dst = dig((1 + r.nextInt(w - 2),1 + r.nextInt(h - 2)),fill) ++ Map((1,1) -> "S", (w - 2,h - 2) -> "F")
		printMaze(dst)
		
	}
}

log

########################################
#S#   #   # #     # #   ##     #       #
#   #   #    ## #   # #    # ##  ## ## #
# ## ##  ###   # # #   ## ###   ## #   #
# #    #    ##   # # #  # ### #    # # #
# # ## ####   ##   #  ###  #  # ####  ##
# #  #    # # # # #  #   #  #  #    # ##
#  #  # # ###    #  #  #  #   #  ## #  #
##  # ###    # # # # # ##  ###  #    # #
#  ##    ### #  ## # #   #     ## ## # #
# #  ###   #   #      ##  # ###   # #  #
#   #   ##  # #  # # # ##  #  # ##    ##
# ##  #   #  #  # # #   ##  # #  # # # #
#   # ###  #   #      #    ##  ### #   #
###  #   #  # #  ######## #   #   #  # #
#  #   # # ### # #    #  ## # # #  #  ##
# ### #     #  #  # #  #    #   ##  #  #
#  # #  ## #  # #   ##  # ## ### ##   ##
##     #     #    #   #   #         # F#
########################################