#include <iostream>
#include "poly.h"
#include <algorithm> //max min
using namespace std;
poly::poly() {
	this->wsp = new double[1];
	this->wsp[0] = 0.0;
	this->size = 1;
}

poly::poly(double a) {
	this->wsp = new double[1];
	this->wsp[0] = a;
	this->size = 1;
}
bool operator==(const poly& a, const poly& b) {
	return (a.size == b.size && a.wsp == b.wsp);
}
poly& poly::operator=(const poly& a) {
	if (*this == a || a.wsp == NULL)
		return *this;
	delete[] wsp;
	this->wsp = new double[a.size];
	if (wsp == NULL)
		exit(2);
	size = a.size;
	memcpy(this->wsp, a.wsp, size * sizeof(double));
	return *this;
}
double& poly::operator[](int index) {
	if (index < size)
		return this->wsp[index];
	else {
		double * realok=new double[index+1];
		if (realok == NULL) {
			delete[] this->wsp;
			abort();
		}
		/*for (int i = 0; i < this->size; i++) {
			realok[i] = 0;
		}*/
		memcpy(realok, this->wsp,(this->size)*sizeof(double));
		/*for (int i = 0; i < this->size; i++) {
			realok[i] = this->wsp[i];
		}*/
		delete[] this->wsp;
		this->wsp = realok;
		this->size = index + 1;
		return this->wsp[index];
	}
}
poly operator+(const poly& a, const poly& b) {
	poly wynik;
	wynik.wsp = new double[max(a.size, b.size)];
	wynik.size = max(a.size, b.size);
	//wynik.wsp.resize(max(a.wsp.size(), b.wsp.size()), 0.0);
	auto i = 0;
	for (i = 0; i != max(a.size, b.size); i++) {
		wynik.wsp[i] = a.wsp[i] + b.wsp[i];
	}
	if (wynik.size == a.size) {
		for (auto j = i; j != a.size; j++)
			wynik.wsp[j] = a.wsp[j];
	}
	else {
		for (auto j = i; j != b.size; j++)
			wynik.wsp[j] = b.wsp[j];
	}
	return wynik;
}
poly operator*(const poly & a, const poly & b) {
	poly wynik;
	wynik.wsp = new double[a.size + b.size - 1];
	wynik.size = a.size + b.size - 1;
	for (auto i = 0; i != wynik.size; i++) wynik[i] = 0;
	for (auto i = 0; i < a.size; i++) {
		for (auto j = 0; j < b.size; j++) {
			wynik[i + j] += a.wsp[i] * b.wsp[j];
		}
	}
	return wynik;
}
poly operator*(const double& a, const poly & b) {
	poly wynik;
	wynik.wsp= new double[b.size];
	wynik.size = b.size;
	for (auto i = 0; i != b.size; i++) {
		wynik.wsp[i] = a * b.wsp[i];
	}
	return wynik;
}

double poly::operator()(const double& a) {
	double suma = 0.0;
	for (auto i = size; i >= 0; i--) {
		suma += this->wsp[i];
		if (i - 1 != this->wsp[0])
			suma *= a;
	}
	return suma;
}
ostream& operator<<(ostream & s, const poly & a) {
	auto potega = a.size - 1;
	if (potega == -1) {
		s << 0;
		return s;
	}
	for (auto i = a.size-1; i != 0; i--, potega--) {
		double index = a.wsp[i];
		if (index != 0) {
			if (index > 0 && potega != a.size - 1)
				s << " + ";
		}
		if (potega == 0) s << index;
		else if (index == 1) s << "x";
		else if (index == -1) s << "-x";
		else if (index == 0) s << " + 0x";
		else s << index << "x";
		if (potega > 1) s << "^" << potega;
	}
	return s;
}