Submission #423503

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Source Code Expand

import scala.collection.immutable.Stack
import scala.annotation.tailrec

object Main {

  val Array(h,w,_*) = readLine.split(" ").map(_.toInt)
  val grid = for(i <- 0 until h) yield readLine

  type Cell = (Int,Int)

  private[this] val used = Array.fill(w*h)(0)

  @tailrec
  def dfs(stk: Stack[Cell]): Boolean = {
    def next(now: Cell): List[Cell] = {
      List((0,-1), (1,0), (0,1), (-1,0))
      .flatMap{case (dx:Int, dy:Int) => List((now._1 + dx, now._2 + dy))}
      .filter((d:Cell) => 0 <= d._1 && 0 <= d._2 && d._1 < w && d._2 < h)
      .filter((d:Cell) => grid(d._2)(d._1)!='#' && used(d._1+d._2*w)==0)
    }

    val (now, res) = stk.pop2
    used(now._1+now._2*w)=1

    if(grid(now._2)(now._1)=='g') true
    else {
      val nx = next(now)
      if(res.size + nx.size == 0) false
      else dfs(res ++ nx)
    }
  }

  def main (args: Array[String]): Unit = {
    val res = for{
      sy <- 0 until h
      sx <- 0 until w
      if(grid(sy)(sx)=='s')
    } yield dfs(Stack((sx,sy)))

    println(if(res.fold(false)(_ | _))"Yes" else "No")
  }
}

Submission Info

Compile Error

warning: there were four deprecation warnings; re-run with -deprecation for details
one warning found

Judge Result