polynomialtypeimp.cpp

这是学习《Data Structures Using C++》

#include <iostream>
#include <cmath>
#include "polynomialType.h"

using namespace std;

polynomialType::polynomialType(int size) 
          : arrayListType<double>(size)
{
	length = size;
	for(int i = 0; i < size; i++)
		list[i] = 0;
}

double polynomialType::operator() (double x)
{
	double value = 0.0;

	for(int i = 0; i < length; i++)
	{
		if(list[i] != 0.0)
			value = value + list[i] * pow(x,i);
	}

	return value;

}

polynomialType polynomialType::operator+
               (const polynomialType& right)
{
	int size = max(length, right.length);
	int i;

	polynomialType temp(size);

	for(i = 0; i < min(length, right.length); i++)
		temp.list[i] = list[i] + right.list[i];

	if(size == length)
		for(i = min(length, right.length); i < length; i++)
			temp.list[i] = list[i];
	else
		for(i = min(length, right.length); i < right.length; i++)
			temp.list[i] = right.list[i];

	return temp;

}

polynomialType polynomialType::operator-
               (const polynomialType& right)
{
	int size = max(length, right.length);
	int i;

	polynomialType temp(size);

	for(i = 0; i < min(length, right.length); i++)
		temp.list[i] = list[i] - right.list[i];

	if(size == length)
		for(i = min(length, right.length); i < length; i++)
			temp.list[i] = list[i];
	else
		for(i = min(length, right.length); i < right.length; i++)
			temp.list[i] = -right.list[i];

	return temp;

}

polynomialType polynomialType::operator*
               (const polynomialType& right)
{
	polynomialType temp = right;
	
	cout<<"See Programming Exercise 10"<<endl;

	return temp;
}

int polynomialType::min(int x, int y)
{
	if(x <= y)
		return x;
	else
		return y;
}

int polynomialType::max(int x, int y)
{
	if(x >= y)
		return x;
	else
		return y;
}

ostream& operator<<(ostream& os, const polynomialType& p)
{
	int i;
	int indexFirstNonzeroCoeff = 0;

	for(i = 0; i < p.length; i++)
		if(p.list[i] != 0.0)
		{
			indexFirstNonzeroCoeff = i;
			break;
		}

	if(indexFirstNonzeroCoeff < p.length)
	{
		if(indexFirstNonzeroCoeff == 0)
			os<<p.list[indexFirstNonzeroCoeff]<<" ";
		else
			os<<p.list[indexFirstNonzeroCoeff]<<"x^"
			  <<indexFirstNonzeroCoeff<<" ";

		for(i = indexFirstNonzeroCoeff + 1; i < p.length; i++)
		{
			if(p.list[i] != 0.0)
				if(p.list[i] >= 0.0)
					os<<"+ "<<p.list[i]
						<<"x^"<<i<<" ";
				else
					os<<"- "<<-p.list[i]
						<<"x^"<<i<<" ";
		}
	}
    else
		os<<"0";

	return os;
}

istream& operator>>(istream& is, polynomialType& p)
{
	cout<<"The degree of this polynomial is: "
		<<p.length - 1<<endl;
	for(int i = 0; i < p.length; i++)
	{
		cout<<"Enter the coefficient of x^"<<i<<": ";
		is>>p.list[i];
	}

	return is;
}