dans.java

import java.util.*;

public class TicTacToe {
	public static boolean DEBUG = true;
	public static int EMPTY = 0;
	public static int O = 1;
	public static int X = 2;
	public String boardString;
	
	public TicTacToe(String boardString) {
		this.boardString = boardString;
		if (DEBUG) System.out.printf("board: %s\n", this.boardString);
	}

	public int firstEmptySpace() {
		for (int i = 0; i < 10; i++) {
			if (DEBUG) System.out.printf("board: %d\n", i);
			if (DEBUG) System.out.printf("board: %s\n", boardString.substring(i, i+1));
			if (DEBUG) System.out.printf("foo\n");
			if (boardString.substring(i, i+1).equals("-")) {
				if (DEBUG) System.out.printf("returning: %d\n", i);
				return i;
			}
		}
		return 0;
	}
	
	public int randomEmptySpace() {
		ArrayList<Integer> emptySpaces = emptySpaces();
		Random generator = new Random();
		int r = generator.nextInt(emptySpaces.size());
		return (int) emptySpaces.get(r);
	}
	
	public ArrayList<Integer> emptySpaces() {
		ArrayList<Integer> list = new ArrayList<Integer>();
		for (int i = 0; i < 9; i++) {
			if(isEmptySpace(i))
				list.add((Integer) i);
		}
		return list;
	}
	
	public int strategy() {
		// rows
		for(int row = 0; row < 3; row++) {
			if (DEBUG) System.out.printf("row: %d\n", row);
			if (DEBUG) System.out.printf("mytokensinrow: %d\n", myTokensInRow(row));
			if (myTokensInRow(row) == 2 && firstEmptySpaceInRow(row) != -1)
				return firstEmptySpaceInRow(row);
		}
		
		// columns
		for(int col = 0; col < 3; col++) {
			if (DEBUG) System.out.printf("col: %d\n", col);
			if (DEBUG) System.out.printf("mytokensincol: %d\n", myTokensInCol(col));
			if (DEBUG) System.out.printf("firstemptyincol(%d): %d\n", col, firstEmptySpaceInCol(col));
			if (myTokensInCol(col) == 2 && firstEmptySpaceInCol(col) != -1)
				return firstEmptySpaceInCol(col);
		}
		return firstEmptySpace();
	}
	
	public int whoAmI() {
		int numO = count(X);
		int numX = count(O);
		if (numO > numX)
			return X;
		else {
			if (numO == numX)
				return O;
			else
				return X;
		}
	}
	
	public int count(int piece) {
		int c = 0;
		for (int i = 0; i < 3; i++)
			for (int j = 0; j < 3; j++)
				if (tokenAt(i, j) == piece)
					c++;
		return c;
	}
	
	public boolean isEmptySpace(int i) {
		return boardString.substring(i, i+1).equals("-");
	}
	
	public int myTokensInRow(int row) {
		int count = 0;
		for(int col = 0; col < 3; col++) {
			if (tokenAt(row, col) == whoAmI())
				count++;
		}
		return count;
	}
	
	public int firstEmptySpaceInRow(int row) {
		for(int col = 0; col < 3; col++) {
			if (tokenAt(row, col) == EMPTY)
				return row*3 + col;
		}
		return -1;
	}
	
	public int myTokensInCol(int row) {
		int count = 0;
		for(int col = 0; col < 3; col++) {
			if (tokenAt(col, row) == whoAmI())
				count++;
		}
		return count;
	}
	
	public int firstEmptySpaceInCol(int col) {
		for(int row = 0; row < 3; row++) {
			if (tokenAt(row, col) == EMPTY)
				return row*3 + col;
		}
		return -1;
	}
	
	public int tokenAt(int row, int col) {
		String tokenString = boardString.substring(row*3 + col, row*3 + col + 1);
		if (tokenString.equals("o"))
			return O;
		else if (tokenString.equals("x"))
			return X;
		else if (tokenString.equals("-"))
			return EMPTY;
		System.out.printf("fail 1\n");
		return -1;
	}
	
	public static void main (String[] args) {
		String b = args[0];
		TicTacToe ttt = new TicTacToe(b);
		if (DEBUG) System.out.printf("whoami: %d\n", ttt.whoAmI());
		System.out.printf("%d\n", ttt.strategy());
	}
}