Added C++ agent

As a result, found an issue where qchess was printing "-1" as the index whenever a King was selected.
I don't know why that didn't break the python agent, but it definitely breaks the C++ agent, so I fixed it.

agents/agent++/Makefile

+# Makefile for agent++
+
+CXX = g++ -std=gnu++0x -g -Werror -Wall -pedantic 
+LINK_OBJ = qchess.o agent.o main.o
+
+
+BIN = agent++
+
+$(BIN) : $(LINK_OBJ)
+	$(CXX) -o $(BIN) $(LINK_OBJ) 
+
+%.o : %.c
+	$(CXX) $(FLAGS) -c $<
+
+clean :
+	$(RM) $(BIN) $(OBJ) $(LINK_OBJ)
+
+clean_full: #cleans up all backup files
+	$(RM) $(BIN) $(OBJ) $(LINK_OBJ)
+	$(RM) *.*~
+	$(RM) *~

agents/agent++/agent.cpp

+/**
+ * agent++ : A Sample agent for UCC::Progcomp2013
+ * @file agent.cpp
+ * @purpose Definition of Agent class
+ */
+
+#include "agent.h"
+#include <cassert> // for sanity checks
+
+using namespace std;
+
+/**
+ * @constructor Agent
+ * @param new_colour - colour of the Agent
+ */
+Agent::Agent(const string & new_colour) : colour(new_colour), board(), selected(NULL)
+{
+	assert(colour == "white" || colour == "black");
+}
+
+/**
+ * @destructor ~Agent
+ */
+Agent::~Agent()
+{
+
+}
+
+/**
+ * @funct Select
+ * @purpose Selects a piece at random
+ * @returns Square containing the selected piece
+ */
+Square & Agent::Select()
+{
+	vector<Piece*> & v = board.pieces(colour); // get pieces
+	int choice = rand() % v.size(); // pick random index
+	Piece * p = v[choice]; // get piece at the index
+	assert(p->colour == colour);
+	selected = p; // update selected
+	//cerr << "Selected " << p->x << "," << p->y << " [" << p->types[0] << "," << p->types[1] << "]\n";
+	return board.square(p->x, p->y); // get Square from board
+}
+
+/**
+ * @funct Move
+ * @purpose Pick a square to move a selected piece into
+ * @returns Square to move last selected piece into
+ */
+Square & Agent::Move()
+{
+	assert(selected != NULL);
+	vector<Square*> moves; // all possible moves for selected piece
+	board.Get_moves(selected, moves); // populate possible moves
+	assert(moves.size() > 0); 
+	int choice = rand() % moves.size(); // pick random index
+	return *(moves[choice]); // return that move
+}
+
+/**
+ * @funct Run
+ * @purpose The "Game Loop" for the agent; read commands and call appropriate function to make responses
+ * @param in - Stream to read input from (use std::cin)
+ * @param out - Stream to write output to (use std::cout)
+ */
+void Agent::Run(istream & in, ostream & out)
+{
+	string cmd; // buffer for tokens
+	while (in.good())
+	{
+		in >> cmd; // read first token only
+		if (cmd == "QUIT")
+		{
+			break;
+		}
+		else if (cmd == "SELECTION?")
+		{
+			Square & s = Select(); // get selection
+			out << s.x << " " << s.y  << "\n"; // return response through output
+		}
+		else if (cmd == "MOVE?")
+		{
+			Square & s = Move(); // get move
+			out << s.x << " " << s.y << "\n"; // return response through output
+		}
+		else
+		{
+			// There were multiple tokens...
+			stringstream s(cmd);
+			int x; int y;
+			s >> x; // Convert first token (in cmd) to an int
+			in >> y; // Read second token from in
+			
+			in >> cmd; // Read third token
+			
+			if (cmd == "->") // Token indicates a move was made
+			{
+				int x2; int y2; // remaining two tokens indicate destination
+				in >> x2; in >> y2;
+				board.Update_move(x, y, x2, y2); // update the board
+			}
+			else
+			{
+				// Tokens are for a selection
+				int index; stringstream s2(cmd); 
+				s2 >> index; // convert third token to an index
+				in >> cmd; // Read fourth token - the new type of the piece
+				board.Update_select(x, y, index, cmd); // update the board
+			}
+			
+		}
+	}
+}

agents/agent++/agent.h

+/**
+ * agent++ : A Sample agent for UCC::Progcomp2013
+ * @file agent.h
+ * @purpose Declaration of Agent class
+ */
+
+#ifndef _AGENT_H
+#define _AGENT_H
+
+#include <iostream>
+#include <sstream>
+#include "qchess.h" // Declarations of Board, Piece and Square classes; see also qchess.cpp
+
+/**
+ * @class Agent
+ * @purpose Class that represents an agent which will play qchess
+ */
+class Agent
+{
+	public:
+		Agent(const std::string & colour); // initialise with colour
+		virtual ~Agent(); // destructor
+
+		void Run(std::istream & in, std::ostream & out); // agent run loop, specify input and output streams
+		
+		virtual Square & Select(); // select a square (default: random square containing one of my pieces)
+		virtual Square & Move(); // select a move (default: random valid move for selected piece)
+
+	
+	protected:
+		const std::string colour; // colour of the agent; do not change it
+		Board board; // board, see qchess.h
+		Piece * selected; // last piece chosen by Agent::Select, see qchess.h
+		
+};
+
+#endif //_AGENT_H
+
+//EOF

agents/agent++/main.cpp

+/**
+ * agent++ : A Sample agent for UCC::Progcomp2013
+ * @file main.cpp
+ * @purpose The main function 
+ */
+#include <cstdlib>
+#include <cstdio>
+#include <iostream>
+
+#include "agent.h" // Declarations for agent, see also agent.cpp
+
+using namespace std;
+
+/**
+ * @funct main
+ * @purpose The main function; starts the agent
+ * @param argc - Number of arguments, unused
+ * @param argv - Argument string array, unused
+ */
+int main(int argc, char ** argv)
+{
+	srand(time(NULL)); // seed random number generator
+
+	string colour; cin >> colour; // first read the colour of the agent
+	Agent agent(colour); // create an agent using the colour
+	agent.Run(cin, cout); // run the agent (it will read from cin and output to cout)
+	
+	return 0; // Don't use exit(3), because it causes memory leaks in the C++ stdlib
+}

agents/agent++/qchess.cpp

+/**
+ * agent++ : A Sample agent for UCC::Progcomp2013
+ * @file qchess.h
+ * @purpose Definitions for game related classes; Piece, Square, Board
+ */
+
+#include "qchess.h"
+#include <cassert>
+
+using namespace std;
+
+/**
+ * @constructor
+ * @param new_x, new_y - Position of piece
+ * @param new_colour - Colour of piece
+ * @param type1, type2 - Types of piece
+ * @param index - Index for initial type of piece
+ */
+Piece::Piece(int new_x, int new_y, const string & new_colour, const string & type1, const string & type2, int index)
+	: x(new_x), y(new_y), colour(new_colour), type_index(index), types(), current_type()
+{
+	types[0] = type1; types[1] = type2;
+	if (index < 0 || index >= 2)
+	{
+		current_type = "unknown";
+	}
+	else
+	{
+		current_type = types[index];
+	}
+}
+
+/**
+ * @constructor
+ * @param cpy - Piece to copy construct from
+ */
+Piece::Piece(const Piece & cpy) : x(cpy.x), y(cpy.y), colour(cpy.colour), type_index(cpy.type_index)
+{
+	types[0] = cpy.types[0];
+	types[1] = cpy.types[1];
+}
+
+/**
+ * @constructor
+ * @param choose_types - Indicates whether Board should setup the 2nd types of pieces; default false
+ */
+Board::Board(bool choose_types)
+{
+
+	// initialise all the Squares
+	for (int x = 0; x < BOARD_WIDTH; ++x)
+	{
+		for (int y = 0; y < BOARD_HEIGHT; ++y)
+		{
+			grid[x][y].x = x;
+			grid[x][y].y = y;
+		}
+	}
+
+	// const arrays simplify below code
+	string colours[] = {"black", "white"};
+	string types[] = {"rook", "bishop", "knight", "queen", "pawn"};
+
+	// frequency of each type of piece
+	map<string, int> freq;
+	freq["rook"] = 2;
+	freq["bishop"] = 2;
+	freq["knight"] = 2;
+	freq["queen"] = 1;
+	freq["pawn"] = 8;
+	
+	// for white and black...
+	for (int i = 0; i < 2; ++i)
+	{
+		vector<Piece*> & v = pieces(colours[i]); // get vector of pieces
+		
+		
+
+		// add pawns
+		int y = (i == 0) ? 1 : BOARD_HEIGHT-2;
+		for (int x = 0; x < BOARD_WIDTH; ++x)
+		{	
+			Piece * p = new Piece(x, y, colours[i], "pawn", "unknown");
+			v.push_back(p);
+		}		
+
+		// add other pieces
+		y = (i == 0) ? 0 : BOARD_HEIGHT-1;
+		v.push_back(new Piece(0, y, colours[i], "rook", "unknown"));
+		v.push_back(new Piece(BOARD_WIDTH-1, y, colours[i], "rook", "unknown"));
+		v.push_back(new Piece(1, y, colours[i], "knight", "unknown"));
+		v.push_back(new Piece(BOARD_WIDTH-2, y, colours[i], "knight", "unknown"));
+		v.push_back(new Piece(2, y, colours[i], "bishop", "unknown"));
+		v.push_back(new Piece(BOARD_WIDTH-3, y, colours[i], "bishop", "unknown"));
+		v.push_back(new Piece(3, y, colours[i], "queen", "unknown"));
+
+		Piece * k = new Piece(4, y, colours[i], "king", "king", 1);
+		if (i == 0)
+			white_king = k;
+		else
+			black_king = k;
+		v.push_back(k);
+		
+		// add to board and choose second types if required
+		map<string, int> f(freq); 
+		int type2;
+		for (unsigned j = 0; j < v.size(); ++j)
+		{
+			Piece * p = v[j];
+			grid[p->x][p->y].piece = p;
+			if (choose_types)
+			{
+				if (p->types[1] != "unknown")
+					continue;
+	
+				do
+				{
+					type2 = rand() % 5;
+				} while (f[types[type2]] <= 0);
+				f[types[type2]] -= 1;
+	
+				p->types[1] = types[type2];			
+			}
+
+			
+		}
+
+		
+
+	}
+
+}
+
+/**
+ * @constructor
+ * @param cpy - Board to copy construct from; each Piece in the copy will be *copied*
+ *		The Piece's in the copied Board may be altered without affecting the original
+ */
+Board::Board(const Board & cpy)
+{
+	for (int x = 0; x < BOARD_WIDTH; ++x)
+	{
+		for (int y = 0; y < BOARD_HEIGHT; ++y)
+		{
+			grid[x][y].x = x;
+			grid[x][y].y = y;
+
+			if (cpy.grid[x][y].piece != NULL)
+			{
+				grid[x][y].piece = new Piece(*(cpy.grid[x][y].piece));
+				pieces(grid[x][y].piece->colour).push_back(grid[x][y].piece);
+			}
+		}
+	}
+}
+
+/**
+ * @destructor
+ */
+Board::~Board()
+{
+	white.clear();
+	black.clear();
+	for (int x = 0; x < BOARD_WIDTH; ++x)
+	{
+		for (int y = 0; y < BOARD_HEIGHT; ++y)
+		{
+			delete grid[x][y].piece;
+		}
+	}
+
+}
+
+/**
+ * @funct Update_select
+ * @purpose Update Piece that has been selected
+ * @param x, y - Position of Piece to update
+ * @param index - 0 or 1 - State the Piece "collapsed" into
+ * @param type - Type of the Piece
+ */
+void Board::Update_select(int x, int y, int index, const string & type)
+{
+	cerr << "Updating " << x << "," << y << " " << grid[x][y].piece << " " << index << " " << type << "\n";
+	Square & s = grid[x][y];
+	assert(s.piece != NULL);
+	assert(index >= 0 && index < 2);
+	s.piece->type_index = index;
+	s.piece->types[index] = type;
+	s.piece->current_type = type;
+}
+
+/**
+ * @funct Update_move
+ * @purpose Move a Piece from one square to another
+ * @param x1, y1 - Coords of Square containing moving Piece
+ * @param x2, y2 - Coords of Square to move into
+ * 	NOTE: Any Piece in the destination Square will be destroyed ("taken")
+ *		and the Board's other members updated accordingly
+ */
+void Board::Update_move(int x1, int y1, int x2, int y2)
+{
+	Square & s1 = grid[x1][y1];
+	Square & s2 = grid[x2][y2];
+	if (s2.piece != NULL)
+	{
+		vector<Piece*> & p = pieces(s2.piece->colour);
+		vector<Piece*>::iterator i = p.begin();
+		while (i != p.end())
+		{
+			if (*i == s2.piece)
+			{
+				p.erase(i);
+				break;
+			}
+			++i;
+		}
+		Piece * k = king(s2.piece->colour);
+		if (k == s2.piece)
+		{
+			if (k->colour == "white")
+				white_king = NULL;
+			else
+				black_king = NULL;
+		}
+
+		delete s2.piece;
+	}	
+
+	s1.piece->x = s2.x;
+	s1.piece->y = s2.y;
+
+	s2.piece = s1.piece;
+	s1.piece = NULL;	
+}
+
+/**
+ * @funct Get_moves
+ * @purpose Get all moves for a Piece and store them
+ * @param p - Piece
+ * @param v - vector to store Squares in. Will *not* be cleared.
+ */
+void Board::Get_moves(Piece * p, vector<Square*> & v)
+{
+	assert(p->current_type != "unknown");
+	int x = p->x; int y = p->y;
+	if (p->current_type == "king")
+	{
+		Move(p, x+1, y, v);
+		Move(p, x-1, y, v);
+		Move(p, x, y+1, v);
+		Move(p, x, y-1, v);
+		Move(p, x+1, y+1, v);
+		Move(p, x+1, y-1, v);
+		Move(p, x-1, y+1, v);
+		Move(p, x-1, y-1, v);
+	}
+	else if (p->current_type == "knight")
+	{
+		Move(p, x+2, y+1, v);
+		Move(p, x+2, y-1, v);
+		Move(p, x-2, y+1, v);
+		Move(p, x-2, y-1, v);
+		Move(p, x+1, y+2, v);
+		Move(p, x-1, y+2, v);
+		Move(p, x+1, y-2, v);
+		Move(p, x-1, y-2, v); 
+	}
+	else if (p->current_type == "pawn")
+	{
+		int y1 = (p->colour == "white") ? BOARD_HEIGHT-2 : 1;
+		int y2 = (p->colour == "white") ? y1 - 2 : y1 + 2;
+		if (p->types[0] == "pawn" && p->y == y1)
+		{
+			
+			Move(p, x, y2, v);
+		}
+		y2 = (p->colour == "white") ? y - 1 : y + 1;
+		Move(p, x, y2, v);
+
+		if (Valid_position(x-1, y2) && grid[x-1][y2].piece != NULL)
+			Move(p, x-1, y2, v);
+		if (Valid_position(x+1, y2) && grid[x+1][y2].piece != NULL)
+			Move(p, x+1, y2, v);
+	}
+	else if (p->current_type == "bishop")
+	{
+		Scan(p, 1, 1, v);
+		Scan(p, 1, -1, v);
+		Scan(p, -1, 1, v);
+		Scan(p, -1, -1, v);
+	}
+	else if (p->current_type == "rook")
+	{
+		Scan(p, 1, 0, v);
+		Scan(p, -1, 0, v);
+		Scan(p, 0, 1, v);
+		Scan(p, 0, -1, v);
+	}
+	else if (p->current_type == "queen")
+	{
+		Scan(p, 1, 1, v);
+		Scan(p, 1, -1, v);
+		Scan(p, -1, 1, v);
+		Scan(p, -1, -1, v);
+		Scan(p, 1, 0, v);
+		Scan(p, -1, 0, v);
+		Scan(p, 0, 1, v);
+		Scan(p, 0, -1, v);
+	}
+
+} 
+
+/**
+ * @funct Move
+ * @purpose Add a move to the vector, if it is valid
+ * @param p - Piece that would move
+ * @param x, y - Destination Square coords
+ * @param v - vector to put the destination Square in, if the move is valid
+ */
+void Board::Move(Piece * p, int x, int y, vector<Square*> & v)
+{
+	if (Valid_position(x, y) && (grid[x][y].piece == NULL || grid[x][y].piece->colour != p->colour))
+	{
+		v.push_back(&(grid[x][y]));
+	}
+	//else
+	//	cerr << "Square " << x << "," << y << " invalid; " << grid[x][y].piece << "\n";
+}
+
+/**
+ * @funct Scan
+ * @purpose Add moves in a specified direction to the vector, until we get to an invalid move
+ * @param p - Piece to start scanning from
+ * @param vx, vy - "velocity" - change in coords each move
+ * @param v - vector to store valid Squares in
+ */
+void Board::Scan(Piece * p, int vx, int vy, vector<Square*> & v)
+{
+	int x = p->x + vx;
+	int y = p->y + vy;
+	while (Valid_position(x, y) && (grid[x][y].piece == NULL || grid[x][y].piece->colour != p->colour))
+	{
+		v.push_back(&(grid[x][y]));
+		x += vx;
+		y += vy;
+	}
+}

agents/agent++/qchess.h

+/**
+ * agent++ : A Sample agent for UCC::Progcomp2013
+ * @file qchess.h
+ * @purpose Declarations for game related classes; Piece, Square, Board
+ */
+
+#ifndef _QCHESS_H
+#define _QCHESS_H
+
+
+// board height and width (don't change!)
+#define BOARD_HEIGHT 8
+#define BOARD_WIDTH 8
+
+#include <string>
+#include <vector>
+#include <map>
+#include <cstdlib>
+#include <iostream>
+
+/**
+ * @class Piece
+ * @purpose Represent a quantum chess piece
+ */
+class Piece
+{
+	public:
+		Piece(int x, int y, const std::string & new_colour, const std::string & type1 = "unknown", const std::string & type2 = "unknown", int new_type_index = -1); // constructor
+		Piece(const Piece & cpy); // copy constructor
+		virtual ~Piece() {} // destructor
+
+		int x; int y; // position of the piece
+		std::string colour; // colour of the piece
+		int type_index; // indicates state the piece is in; 0, 1, or -1 (unknown)
+		std::string types[2]; // states of the piece
+		std::string current_type; // current state of the piece
+		
+
+};
+
+/**
+ * @class Square
+ * @purpose Represent a Square on the board; not necessarily occupied
+ */
+class Square
+{
+	public:
+		Square() : x(-1), y(-1), piece(NULL) {} // constructor
+		Square(int new_x, int new_y, Piece * new_piece = NULL) : x(new_x), y(new_y), piece(new_piece) {} //UNUSED
+		Square(const Square & cpy) : x(cpy.x), y(cpy.y), piece(cpy.piece) {} // copy constructor (UNUSED)
+		virtual ~Square() {} //destructor
+		int x;	int y; // position of the square
+		Piece * piece; // Piece that is in the Square (NULL if unoccupied)
+};
+
+/**
+ * @class Board
+ * @purpose Represent a quantum chess board
+