3.poly

#include <iostream>
#include<cmath>
using namespace std;

class poly
{
public:
	int* a;
	int size;
public:
	int eval(int val);
	void add(poly *p1,poly *p2,int m,int n);
	friend ostream& operator<<(ostream& out, poly& p);
	friend istream& operator>>(istream& in, poly& p);
	void mul(poly* p1, poly* p2, int m, int n);

};

int poly::eval(int val)
{
	int result=0;

	for (int i = size; i >= 0; i--)
	{
		result += a[i] * pow(val, i);
	}
	return result;
}

istream& operator>>(istream& in, poly& p)
{
	for (int i = p.size; i >= 0; i--)
	{
		cout << "Enter coeff for deg " << i << endl;
		in >> p.a[i];
	}

	return in;
}

ostream& operator<<(ostream& out, poly& p)
{
	cout << "Display..." << endl;

	for (int i = p.size; i >= 0; i--)
	{
		if (i == 0)
			cout <<"("<<p.a[i]<<")" ;
		else
			cout <<"("<< p.a[i] << "x^" << i << ") + ";
	}
	return out;
}

void poly::add(poly *p1,poly *p2,int m,int n)
{
	int i;

	for (i = 0 ; i <= m && i<=n; i++)
	{
		a[i] = p1->a[i] + p2->a[i];
	}

	if (i == n + 1)
	{
		for (int j = n + 1; j <= m; j++)
		{
			a[j] = p1->a[j];
		}
	}
	else
	{
		for (int j = m + 1; j <= n; j++)
		{
			a[j] = p2->a[j];
		}
	}

}

void poly::mul(poly* p1, poly* p2, int m, int n)
{
	for (int i = 0; i <= size; i++)
	{
		a[i] = 0;
	}
 
	for (int i = 0; i <= m; i++)
	{
		for (int j = 0; j <= n; j++)
		{
			a[i+j] += (p1->a[i] * p2->a[j]);
		}
			
	}

}

int main()
{
	poly p1;
	poly p2;
	poly p3;
	poly p4;

	int val;

	int m;
	cout << "Enter highest degree of poly" << endl;
	cin >> m;

	p1.size = m;

	p1.a = new int[m];

	cout << "Enter elements of Polynomial" << endl;
	cin >> p1;

	cout << "Polynomial:" << endl;
	cout << p1<<endl;

	cout << "Enter value" << endl;
	cin >> val;

	int ans=p1.eval(val);
	cout << "Result: " << ans << endl;

	cout << "Addition" << endl;

	int n;
	cout << "Enter highest degree of poly" << endl;
	cin >> n;

	p2.size = n;

	p2.a = new int[n];

	cout << "Enter elements of Polynomial" << endl;
	cin >> p2;

	cout << "Polynomial:" << endl;
	cout << p2<<endl;

	cout << "Addition: " << endl;

	if (m > n)
		p3.size = m;
	else
		p3.size = n;

	p3.a = new int[p3.size];

	p3.add(&p1,&p2,m,n);
	cout << p3<<endl;


	cout << "Multiplication" << endl;

	p4.size = m + n;
	p4.a = new int[m + n];

	p4.mul(&p1,&p2,m,n);
	cout << p4;

	return 0;
}