Othello

Othello.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
	
	static int[][] debugInputs = {
			{4, 5},
			{5, 5},
			{5, 4},
			{3, 5},
			{2, 4},
			{1, 3},
			{2, 3},
			{5, 3},
			{3, 2},
			{3, 1}
	};
	
	/*
	static int[][] debugInputs = {
			{4, 5},
			{5, 3},
			{4, 2},
			{3, 5},
			{6, 4},
			{5, 5},
			{4, 6},
			{5, 4},
			{2, 4}
	};
	*/
	

	public static void main(String[] args) {
		Othello oth = new Othello();
		boolean debug = true;
		
		
		if (debug) {
			for (int[] input : debugInputs) {
				oth.put(input[0], input[1]);
				oth.printTable();
				if (oth.isGameEnd()) {
					oth.reportGame();
				}
			}
			return;
		}
		
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String line;
		while (true) {
			oth.printTable();
			try {
				System.out.println("Turn: " + oth.MARKER[oth.turn]);
				System.out.print("Input i j:");
				line = br.readLine();
				String[] tokens = line.split(" ");
				int put_i = Integer.parseInt(tokens[0]);
				int put_j = Integer.parseInt(tokens[1]);
				if (!oth.put(put_i, put_j)) {
					System.out.println("You cannot put " + put_i + " " + put_j);
				};
				if (oth.isGameEnd()) {
					oth.reportGame();
					break;
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
			
		}

	}

}

class Othello {
	static final int SIZE = 8;
	static final int BLACK = 0;
	static final int WHITE = 1;
	static final int EMPTY = 2;
	static	final char[] MARKER = {'*', 'O', ' '};
	static final int[] dx = {0, 1, 0, -1, 1, 1, -1, -1};
	static final int[] dy = {1, 0, -1, 0, 1, -1, 1, -1};
	int[][] table;
	int turn = 0;
	int cnt = 0;
	
	Othello () {
		this.table = new int[SIZE][];
		for (int i = 0; i < SIZE; i++) {
			table[i] = new int[SIZE];
			for (int j = 0; j < SIZE; j++) {
				table[i][j] = EMPTY;
			}
		}
		table[SIZE / 2 - 1][SIZE / 2 - 1] = WHITE;
		table[SIZE / 2][SIZE / 2] = WHITE;
		table[SIZE / 2 - 1][SIZE / 2] = BLACK;
		table[SIZE / 2][SIZE / 2 - 1] = BLACK;
		
	}
	
	boolean put(int i, int j) {
		if (table[i][j] != EMPTY) {
			return false;
		}
		boolean ret = false;
		for (int d = 0; d < 8; d++) {
			if (turnPieces(i, j, i, j, d, true, this.turn)) {
				ret = true;
			}
		}
		if (ret) {
			table[i][j] = this.turn;
			this.turn = getNextTurn();
			cnt += 1;
		}
		return ret;
	}
	
	private boolean canPut(int turn) {
		// 試しに置いてみてひっくり返せる場所があるか確かめる
		for (int d = 0; d < 8; d++) {
			for (int i = 0; i < SIZE; i++) {
				for (int j = 0; j < SIZE; j++) {
					if (turnPieces(i, j, i, j, d, false, turn)) {
						return true;
					}
				}
			}
		}
		return false;
	}
	
	public boolean isGameEnd() {
		// 全部置いた or 両者置く場所がない
		return (cnt == SIZE * SIZE) || (!canPut(BLACK) && !canPut(WHITE));
	}
	
	private int getNextTurn() {
		// 相手が置けない時は再び自分のターンになる
		int nextTurn = (this.turn + 1) % 2;
		if (canPut(nextTurn)) {
			return nextTurn;
		} else {
			return this.turn;
		}
		
	}
	
	private boolean turnPieces(int i, int j, int put_i, int put_j, int dir, boolean is_turn, int turn) {
		// 自分と同じ色のマスを発見したら(true), 戻りながら色を変える
		// 置いた地点は無視
		if (i == put_i && j == put_j) {
			return turnPieces(i + dx[dir], j + dy[dir], put_i, put_j, dir, is_turn, turn);
		}
		if (i < 0 || i >= SIZE || j < 0 || j >= SIZE) {
			return false;
		}
		if (table[i][j] == EMPTY) {
			return false;
		}
		if (table[i][j] == turn) {
			// 置いたコマの隣のコマが同じ色の時はfalse
			int dist = Math.abs(i - put_i) + Math.abs(j - put_j);
			// 上下左右
			if (dir <= 3) {
				return dist != 1;
			// 斜め
			} else {
				return dist != 2;
			}
		}
		boolean ret = turnPieces(i + dx[dir], j + dy[dir], put_i, put_j, dir, is_turn, turn);
		if (ret && is_turn) {
			table[i][j] = turn;
		}
		return ret;
	}
	
	public void printTable() {
		System.out.print(" ");
		for (int i = 0; i < SIZE; i++) {
			System.out.print("|" + i);
		}
		System.out.println("|");
		for (int i = 0; i < SIZE; i++) {
			for (int j = 0; j < SIZE; j++) {
				System.out.print("-+");
			}
			System.out.println("-+");
			System.out.print(i);
			for (int j = 0; j < SIZE; j++) {
				System.out.print("|" + MARKER[table[i][j]]);
			}
			System.out.println("|");
		}
		for (int i = 0; i < SIZE + 1; i++) {
			System.out.print("-+");
		}
		System.out.println("");
		System.out.println("");
	}
	
	public void reportGame() {
		int black_cnt = 0;
		int white_cnt = 0;
		for (int i = 0; i < SIZE; i++) {
			for (int j = 0; j < SIZE; j++) {
				if(table[i][j] == BLACK) {
					black_cnt += 1;
				} else if (table[i][j] == WHITE) {
					white_cnt += 1;
				}
			}
		}
		System.out.println("*: " + black_cnt);
		System.out.println("O: " + white_cnt);
		if (black_cnt > white_cnt) {
			System.out.println("win: *");
		} else if (black_cnt < white_cnt) {
			System.out.println("win: O");
		} else {
			System.out.println("draw");
		}
	}
	
}