// (C) 2013-2014, Sergei Zaychenko, KNURE, Kharkiv, Ukraine

#ifndef _ARITHMETIC_PROGRESSION_HPP_
#define _ARITHMETIC_PROGRESSION_HPP_

/*****************************************************************************/

#include <iostream>

/*****************************************************************************/


class ArithmeticProgression
{

public:

	ArithmeticProgression();
	ArithmeticProgression(double _step, double _initialvalue);
	ArithmeticProgression(double step1);

	const double getInitialValue() const;
	const double getStep()const;

	double getIthElement(int _i);

	double partialSum(int _i, int _k);
	double partialAverage(int _i, int _k);

	bool operator == (const ArithmeticProgression & _ArithmeticProgression) const;
	bool operator != (const ArithmeticProgression & _ArithmeticProgression) const;

	void display(int _i, int _k, std::ostream& disp);
	bool matchesArray(const int* _pElements, int _N);
	ArithmeticProgression makeInverted();


private:

	double m_initialvalue;
	double m_step;

	int m_i;
	int m_k;

	void m_checkRange(int a, int b);
};


inline const double  ArithmeticProgression::getInitialValue() const
{
	return m_initialvalue;
}

inline const double ArithmeticProgression::getStep()const
{
	return m_step;
}



/*****************************************************************************/

#endif //  _ARITHMETIC_PROGRESSION_HPP_