Piezas.h

#ifndef _PIEZAS_H_
#define _PIEZAS_H_
#include <vector>

const int BOARD_ROWS = 3;
const int BOARD_COLS = 4;

enum Piece
{
  	X = 'X',
  	O = 'O',
  	Invalid = '?',
  	Blank = ' '
};

/**
 * Class for representing a Piezas vertical board, which is roughly based
 * on the game "Connect Four" where pieces are placed in a column and 
 * fall to the bottom of the column, or on top of other pieces already in
 * that column. For an illustration of the board, see:
 *  https://en.wikipedia.org/wiki/Connect_Four
 *
 * Board coordinates [row,col] should match with:
 * [2,0][2,1][2,2][2,3]
 * [1,0][1,1][1,2][1,3]
 * [0,0][0,1][0,2][0,3]
 * So that a piece dropped in column 2 should take [0,2] and the next one
 * dropped in column 2 should take [1,2].
**/
class Piezas
{
  private:
  	std::vector < std::vector<Piece> > board;
  	Piece turn;

  public:
  	/**
     * Constructor sets an empty board (3 rows, 4 columns) and 
     * specifies it is X's turn first
    **/
  	Piezas();

  	/**
     * Resets each board location to the Blank Piece value, with a board of the
     * same size as previously specified
    **/
  	void reset();

  	/**
  	 * Places a piece of the current turn on the board, returns what
  	 * piece is placed, and toggles which Piece's turn it is. dropPiece does 
  	 * NOT allow to place a piece in a location where a column is full.
  	 * In that case, placePiece returns Piece Blank value 
  	 * Out of bounds coordinates return the Piece Invalid value
     * Trying to drop a piece where it cannot be placed loses the player's turn
  	**/ 
  	Piece dropPiece(int column);

  	/**
  	 * Returns what piece is at the provided coordinates, or Blank if there
  	 * are no pieces there, or Invalid if the coordinates are out of bounds
  	**/
  	Piece pieceAt(int row, int column);

    /**
     * Returns which Piece has won, if there is a winner, Invalid if the game
     * is not over, or Blank if the board is filled and no one has won ("tie").
     * For a game to be over, all locations on the board must be filled with X's 
     * and O's (i.e. no remaining Blank spaces). The winner is which player has
     * the most adjacent pieces in a single line. Lines can go either vertically
     * or horizontally. If both X's and O's have the same number of pieces in a
     * line, it is a tie.
    **/
  	Piece gameState();
};

#endif /*_PIEZAS_H_*/