Othello

othello.java

import java.net.*;
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;

public class Othello{
	public static final int WHITE=-1;
	public static final int BLACK=1;
	public static final int INVALID=-2;
	public static final int NONE=0;
	public int board[][] = new int[8][8];
	
	private int dirs[] = {1,0,-1};

	public int turn;

	public Othello(){
		for(int i=0;i<8;i++) for(int j=0;j<8;j++) board[i][j] = NONE;
		board[4][4]=board[3][3]=WHITE;
		board[4][3]=board[3][4]=BLACK;
		turn = BLACK;
	}

	public int getStone(int x,int y){
		if(0<=x&&x<8&&0<=y&&y<8) return board[x][y];
		else return INVALID;
	}

	public boolean canPut(int x,int y,int self){
		if(getStone(x,y)!=NONE) return false;
		for(int xd:dirs){
			for(int yd:dirs){
				if(xd==0&&yd==0) continue;
				if(getStone(x+xd,y+yd)==-self){
					for(int xs=x+xd*2,ys=y+yd*2;true;xs+=xd,ys+=yd){
						int stone = getStone(xs,ys);
						if(stone == INVALID || stone==NONE) break;
						else if(stone == self) return true;
					}
				}
			}
		}
		return false;
	}

	public void put(int x,int y,int self){
		ArrayList<Point> rev = new ArrayList<Point>();
		board[x][y] = self;
		for(int xd:dirs){
			for(int yd:dirs){
				if(xd==0&&yd==0) continue;
				if(getStone(x+xd,y+yd)==-self){
					rev.add(new Point(x+xd,y+yd));
					for(int xs=x+xd*2,ys=y+yd*2;true;xs+=xd,ys+=yd){
						int stone = getStone(xs,ys);
						if(stone == INVALID || stone == NONE){
							rev.clear();
							break;
						}else if(stone == self){
							for(Point p:rev) board[p.x][p.y]*=-1;
							rev.clear();
							break;
						}else if(stone == -self){
							rev.add(new Point(xs,ys));
						}
					}
				}
			}
		}
	}
	
	public void changeTurn(){
		turn *= -1;
	}
	
	public void setTurn(int turn){
		this.turn = turn;
	}
	
	public void display(){
		for(int[] line:board){
			for(int p:line){
				String s="";
				if(p==BLACK) s = "黒";
				else if(p==WHITE) s = "白";
				else if(p==NONE) s = "・";
				System.out.print(s);
			}
			System.out.println();
		}
	}
	
	public static void main(String[] args){
		Othello oth = new Othello();
		while(true){
			oth.display();
			Scanner sc = new Scanner(System.in);
			int x = sc.nextInt();
			int y = sc.nextInt();
			if(oth.canPut(x,y,oth.turn)){
				oth.put(x,y,oth.turn);
				oth.changeTurn();
				System.out.println("Put "+oth.turn);
			}else {
				System.out.println("Cannot put there");
			}
		}
	}
}