/**
 * strategy.h
 */

/**
 * This class declares an interface common to all supported
 * algorithms. Context uses this interface to call the algorithm
 * defined by a ConcreteStrategy object.
 */

class Strategy
{

public:
	virtual void AlgorithmInterface() = 0;
};

/**
 * This class implements an algorithm using the Strategy interface.
 */

class ConcreteStrategyA: public Strategy
{

public:
	virtual void AlgorithmInterface()
	{
		// Do something unique.
	};
};

/**
 * This class implements an algorithm using the Strategy interface.
 */

class ConcreteStrategyB: public Strategy
{

public:
	virtual void AlgorithmInterface()
	{
		// Do something unique.
	};
};

/**
 * This class implements an algorithm using the Strategy interface.
 */

class ConcreteStrategyC: public Strategy
{

public:
	virtual void AlgorithmInterface()
	{
		// Do something unique.
	};
};

/**
 * This class is configured with a ConcreteStrategy
 * object. It maintains a reference to a Strategy object.
 * This class may define an interface that lets Strategy
 * access its data.
 */

class Context
{

private:

	/**
	 * Encapsulated instance of a strategy class.
	 */

	Strategy* strategy;

public:

	/**
	 * Default constructor.
	 */

	Context()
	{
		strategy = (Strategy *) 0;
	};

	/**
	 * This method is the one which calls the strategy
	 * object to perform some work.
	 */

public:
	void Operation()
	{
		strategy -> AlgorithmInterface();
	};

public:

	/**
	 * Accessors for the strategy relationship.
	 */

	Strategy* getStrategy()
	{
		return strategy;
	};

	void setStrategy( Strategy* aStrategy )
	{
		strategy = aStrategy;
	};
};