text: /**
   * Demo program for message-board exercise.
   * 
   * Author: Erel Segal-Halevi
   * Since : 2021-03
   */
  
  #include "Board.hpp"
  #include "Direction.hpp"
  using ariel::Direction;
  
  #include <iostream>
  #include <stdexcept>
  using namespace std;
  
  int main() {
  	ariel::Board board;
  	board.post(/*row=*/100, /*column=*/200, Direction::Horizontal, "abcd");
  	cout << board.read(/*row=*/99, /*column=*/201, Direction::Vertical, /*length=*/3) << endl;  
  		// prints "_b_" (starts at row 99 which is empty; then at row 100 there is "b"; then row 101 is empty again).
  	board.post(/*row=*/99, /*column=*/202, Direction::Vertical, "xyz");
  	cout << board.read(/*row=*/100, /*column=*/200, Direction::Horizontal, /*length=*/6) << endl;  
  		// prints "abyd__" (First letters are ab; then y from the "xyz"; then d; then two empty cells).
  
  	board.show(); // shows the board in a reasonable way. For example:
  		//    98:  _________
  		//    99:  ____x____
  		//    100: __abyd___
  		//    101: ____z____
  		//    102: _________
  }
  
  