加分，在线等 c++ polynomial class(多项式类)

#include 
using namespace std;

class Polynomial{
public:
	void Input();
	void Output();
	Polynomial operator+(const Polynomial&);
	Polynomial operator-(const Polynomial&);
private:
	int degree;
	int *coeff;
};

void Polynomial::Input(){
	cout<<"请输入多项式指数degree:";
	cin>>degree;
	coeff=new int[degree+1];
	cout<<"请从高到低输入多项式系数:";
	for(int i=degree;i>=0;i--)
		cin>>coeff[i];
}

void Polynomial::Output(){
	for(int i=degree;i>=0;i--)
	{
		if(i==degree)
		{
			if(coeff[i]==1)
				cout<<"x^"<			else if(coeff[i]==-1)
				cout<<"-x^"<			else 
				cout<		}
		else if(i==1)
		{
			if(coeff[i]==0)
				continue;
			else if(coeff[i]>0)
				cout<<"+"<			else if(coeff[i]<0)
				cout<<"-"<<(-coeff[i])<<"x";
		}
		else if(i==0)
		{
			if(coeff[i]==0)
				cout<			else if(coeff[i]>0)
				cout<<"+"<			else if(coeff[i]<0)
				cout<<"-"<<(-coeff[i])<		}
		else if(i>0&&i		{
			if(coeff[i]==0)
				continue;
			else if(coeff[i]==1)
				cout<<"+x^"<			else if(coeff[i]==-1)
				cout<<"-x^"<			else if(coeff[i]>0)
				cout<<"+"<			else if(coeff[i]<0)
				cout<<"-"<<(-coeff[i])<<"x^"<		}

	}
}

Polynomial Polynomial::operator+(const Polynomial &rhs){
	Polynomial sum;
	int MaxDegree=degree>rhs.degree?degree:rhs.degree;
	int	MinDegree=degree	sum.degree=MaxDegree;
	sum.coeff=new int[sum.degree+1];
	if(rhs.degree==MaxDegree)
	{
		for(int i=0;i			sum.coeff[i]=rhs.coeff[i];
	}
	else{
		for(int i=0;i			sum.coeff[i]=coeff[i];
	}
	for(int i=0;i		sum.coeff[i]=coeff[i]+rhs.coeff[i];
	return sum;
}

Polynomial Polynomial::operator-(const Polynomial &rhs){
	Polynomial sub;
	int MaxDegree=degree>rhs.degree?degree:rhs.degree;
	int	MinDegree=degree	sub.degree=MaxDegree;
	sub.coeff=new int[sub.degree+1];
	if(rhs.degree==MaxDegree)
	{
		for(int i=0;i			sub.coeff[i]=rhs.coeff[i];
	}
	else{
		for(int i=0;i			sub.coeff[i]=coeff[i];
	}
	for(int i=0;i		sub.coeff[i]=coeff[i]-rhs.coeff[i];
	return sub;

}

int main()
{
	Polynomial a,b,c,d;
	a.Input();
	b.Input();
	c=a+b;
	d=a-b;
	a.Output();
	b.Output();
	c.Output();
	d.Output();
	return 0;
}
满意请采纳哦！输出考虑了负系数或者0和1的情况，不懂的可以问，比较全面了。

不知道你满意不。=。=饿，修改完毕

#include 
using namespace std;
class polynomial
{
private:
	int num[100];
	int len;
public:
	polynomial(int* a,int l)
	{
		int i;
		len = l;
		for(i=0;i			num[i] = a[l-i-1];
	}
	polynomial()
	{
		memset(num,0,sizeof(num));
		len = 0;
	}
	int getx(int X)
	{
		int sum,i,x;
		sum =0;
		x=1;
		for(i=0;i		{
			sum+=num[i]*x;
			x*=X;
		}
		return sum;
	}
	void Output()
	{
		int i;
		for(i=len-1;i>=0;i--)
		{
			if(num[i])
			{
				if(num[i]>0 && i != len-1)
					cout<<"+";
				if(!(i!= 0 && num[i]==1))
					cout<				if(i)
					cout<<"x";
				if(i>1)
					cout<<"^"<			}
		}
		cout<	}
	polynomial operator+ (polynomial a)
	{
		polynomial New;
		int i;
		New.len = len >a.len ? len : a.len;
		for(i=0;i			New.num[i] = num[i]+a.num[i];
		return New;
	}
	polynomial operator- (polynomial a)
	{
		polynomial New;
		int i;
		New.len = len >a.len ? len : a.len;
		for(i=0;i			New.num[i] = num[i]-a.num[i];
		return New;
	}
};
int main()
{
	int a[100];
	int n,i;
	cin>>n;
	for(i=0;i		cin>>a[i];
	polynomial Test(a,n);
	polynomial Test3;
	Test.Output();
	cin>>n;
	cout<	Test3 = Test + Test;
	Test3.Output();
	Test3 = Test - Test - Test;
	Test3.Output();
	system("pause");
	return 0;
}

#include
#include
#include
using namespace std;

#define MAX_ITEM 50
class polynomial
{
public:
polynomial(int degree, int coeff[]) {
this->degree = degree;
for (int i = degree; i >= 0; --i) {
this->coeff[i] = coeff[i];
}
}
void output() const {
bool isFirstItem = true;
for (int i = 0; i < item_num(); ++i) {
if (coeff[i]) {
if (!isFirstItem) {
if (coeff[i] > 0)
cout<<"+";
} else {
isFirstItem = false;
}

int cur_degree = degree -i;

if (cur_degree == 0) {
cout< } else if (cur_degree ==1) {
if (coeff[i] == 1) {
cout<<"X";
} else if (coeff[i] == -1) {
cout<<"-X";
} else {
cout< }
} else {
if (coeff[i] == 1) {
cout<<"X^"< } else if (coeff[i] == -1) {
cout<<"-X^"< } else {
cout< }
}
}
}
cout< }
friend polynomial operator+(const polynomial& p1, const polynomial& p2) {
int arr[MAX_ITEM];
int deg = 0;
if (p1.degree > p2.degree) {
deg = p1.degree;
int pos = p1.degree - p2.degree;

for (int i = 0; i < deg+1; ++i) {
if (i < pos) {
arr[i] = p1.coeff[i];
} else {
arr[i] = p1.coeff[i] + p2.coeff[i-pos];
}
}

} else {
deg = p2.degree;
int pos = p2.degree - p1.degree;
for (int i = 0; i < deg+1; ++i) {
if (i < pos) {
arr[i] = p2.coeff[i];
} else {
arr[i] = p2.coeff[i] + p1.coeff[i-pos];
}
}
}
return polynomial(deg, arr);
}
friend polynomial operator-(const polynomial& p1, const polynomial& p2) {
int arr[MAX_ITEM];
int deg = 0;
if (p1.degree > p2.degree) {
deg = p1.degree;
int pos = p1.degree - p2.degree;

for (int i = 0; i < deg+1; ++i) {
if (i < pos) {
arr[i] = p1.coeff[i];
} else {
arr[i] = p1.coeff[i] - p2.coeff[i-pos];
}
}

} else {
deg = p2.degree;
int pos = p2.degree - p1.degree;
for (int i = 0; i < deg+1; ++i) {
if (i < pos) {
arr[i] = p2.coeff[i];
} else {
arr[i] = p2.coeff[i] - p1.coeff[i-pos];
}
}
}
return polynomial(deg, arr);
}
int item_num() const {
return degree + 1;
}

int f(int X) {
int res = 0;
for (int i = 0; i < degree + 1; ++i) {
res += pow(X, degree-i) * coeff[i];
}
return res;
}
private:
int coeff[MAX_ITEM];
int degree;
};

int main()
{
int degree;
int coeff[MAX_ITEM] = {0};

cout<<"poly1's degree:";
cin>>degree;
if (degree < 0) {cout<<"Error"< for (int i = 0; i < degree+1; ++i) {
cout<<"\tcoeff:";
cin>>coeff[i];
}

polynomial poly1(degree, coeff);
cout<<"poly1:"< poly1.output();

cout<<"poly2's degree:";
cin>>degree;
if (degree < 0) {cout<<"Error"<
for (int i = 0; i < degree+1; ++i) {
cout<<"\tcoeff:";
cin>>coeff[i];
}

polynomial poly2(degree, coeff);
cout<<"poly2:"< poly2.output();

polynomial poly3 = poly1 + poly2;
cout<<"poly1 + poly2:"< poly3.output();

int X;
cout<<"set the value of X:";
cin>>X;

int res = poly3.f(X);;
cout<<"res: "< return 0;
}