Scalaを覚えるため、Scalaでオセロゲームを書きました。
いきなりScalaを使うのが難しそうだったため、Javaで下書きしてからScalaで書きました。
以前Javaで下書きしたもの → http://qiita.com/nogitsune413/items/d252a879480480a0697a
なるべく関数プログラミングっぽく書きたかったため、再帰やコレクションを使って、変数の除去に努めました。
他の言語と比べた訳ではないのですが、末尾呼び出し最適化が簡単に書けたので、「こんな簡単に書けるのか」と思いました。
そんな感想です。
import scala.io._
object Main {
val L = 10
val X = 0
val Y = 1
val EMPTY = 0
val BLACK = 1
val WHITE = 2
val DRAW = 3
val WALL = 9
val MOVE = 1
val PASS = 2
val GIVE_UP = 3
val EXIT = 4
val dir = Array(-1,0,1,1,1,0,-1,-1) zip Array(-1,-1,-1,0,1,1,1,0)
var board = Array.ofDim[Int](L,L)
var x,y = -1
var victory = DRAW
val LINE = "------------------------------\n"
val TITLE = "\n" + LINE + "--- オセロ ---\n" + LINE + "\n"
val USAGE = " --- 遊び方 --- \n 縦 5,横 3 のマスに置く => 「5 3」と入力。\n パス： pass \n 投了：give up\n ゲームの終了： exit\n"
val URGES = "\n駒を置いて下さい => "
val RANGE = "^[1-8]$"
val S_BLACK = "黒"
val S_WHITE = "白"
val S_TURN = "番"
val S_DRAW = "\n --- 引き分け --- \n"
val PRE_LINE = "\n --- "
val POST_LINE = " --- \n\n"
val BLACK_TURN = PRE_LINE + S_BLACK + S_TURN + POST_LINE
val WHITE_TURN = PRE_LINE + S_WHITE + S_TURN + POST_LINE
val S_VICTORY = "の勝ち --- \n"
val S_ERROR = "駒が置けません。別のマスを選択して下さい。\n"
val IN_ERROR = "入力に誤りがあります。再度入力して下さい。\n"
val THANKS = "Thank you for playing. Good by the next time."
object Turn{
var thisTurn = BLACK
def show() = {
if(thisTurn==BLACK){print(BLACK_TURN)}
else {print(WHITE_TURN)}
}
def shift() = {
thisTurn = 3 - thisTurn
}
def otherside():Int = {
3 - thisTurn
}
}
object Board{
def init() = {
for(i <- 0 to L - 1 ){
board(0)(i) = WALL
board(9)(i) = WALL
if(i != 0 && i != 9){
for(i <- 1 to 8){
board(i)(0) = WALL
board(i)(9) = WALL
}
}
}
for(i <- 4 to 5){
for(j <- 4 to 5){
if(i==j){
board(i)(j) = WHITE
} else {
board(i)(j) = BLACK
}
}
}
}
def show() = {
print(LINE)
print(" ")
for(i <- 1 to L - 2){
print(i)
if(i<L-2){print(" ")}
}
for(i <- 0 to L-1){
if(0<i && i<L-1){
print("\n " + i + " ")
} else {
print("\n ")
}
for(j <- 0 to L-1){
board(i)(j) match {
case WALL => print("+")
case EMPTY => print("_")
case WHITE => print("o")
case BLACK => print("*")
}
print(" ")
}
if(i<L-1){print(" ")}
else {print("\n")}
}
print(LINE)
}
}
def main(args:Array[String]) = {
Board.init()
println(TITLE)
println(USAGE)
UI
}
def UI:Unit = {
Turn.show()
Board.show()
print(URGES)
val cmd = input()
cmd match {
case MOVE => if(update){
if(isFill){
victory = judge()
show_result()
} else {
Turn.shift()
UI
}
} else {
println(S_ERROR)
UI
}
case PASS => Turn.shift()
UI
case GIVE_UP => victory = Turn.otherside
show_result()
case EXIT => println(THANKS)
}
}
def show_result() = {
var result = ""
victory match {
case BLACK => result = PRE_LINE + S_BLACK + S_VICTORY
case WHITE => result = PRE_LINE + S_WHITE + S_VICTORY
case DRAW => result = S_DRAW
}
println(result)
Board.show()
}
def input():Int = {
val in = readLine()
in match {
case "pass" => PASS
case "exit" => EXIT
case "give up" => GIVE_UP
case _ => val ar = in.split("\\s")
if(ar.length==2 && ar(0).matches(RANGE) && ar(1).matches(RANGE)){
y = ar(0)toInt;
x = ar(1)toInt;
MOVE
} else {
println(IN_ERROR)
println(USAGE)
println(URGES)
input()
}
}
}
def judge():Int = {
if(count(BLACK) < count(WHITE)){
WHITE
} else if(count(BLACK)>count(WHITE)){
BLACK
} else {
DRAW
}
}
def isFill:Boolean = {
if(count(BLACK)+count(WHITE)==8*8){
true
} else {
false
}
}
def count(color:Int):Int = {
count(board,color)
}
def count(brd:Array[Array[Int]],color:Int):Int = {
if(brd.isEmpty){
0
} else {
(brd.first filter (_ == color)).length + count(brd.tail,color)
}
}
def update() = {
if(chk_square()){
flip()
true
} else {
false
}
}
def chk_square():Boolean = {
if(board(y)(x)!=EMPTY){return false}
for(dr <- dir){
if(board(y + dr._2)(x + dr._1)==Turn.otherside){
if(chk_square_a(x + dr._1 * 2,y + dr._2 * 2,dr)){
return true;
}
}
}
false
}
def chk_square_a(a:Int,b:Int,dr:(Int,Int)):Boolean = {
board(b)(a) match {
case n if(n==Turn.thisTurn) => true
case n if(n==Turn.otherside) => chk_square_a(a + dr._1,b + dr._2,dr)
case _ => false
}
}
def flip(){
board(y)(x) = Turn.thisTurn
for(dr <- dir){
if(board(y + dr._2)(x + dr._1)==Turn.otherside){
flip_a(x + dr._1 * 2,y + dr._2 * 2,dr)
}
}
}
def flip_a(a:Int,b:Int,dr:(Int,Int)):Unit = {
board(b)(a) match {
case n if(n==Turn.thisTurn) => flip_b(a - dr._1,b - dr._2,dr)
case n if(n==Turn.otherside) => flip_a(a + dr._1,b + dr._2,dr)
case _ => ;
}
}
def flip_b(a:Int,b:Int,dr:(Int,Int)):Unit = {
if (board(b)(a)!=Turn.otherside){
;
} else {
board(b)(a) = Turn.thisTurn
flip_b(a - dr._1,b - dr._2,dr)
}
}
}