C++链表实现一元多项式（加法、减法、乘法）

C++链表实现一元多项式（加法、减法、乘法）

运行结果如下：

#include
using namespace std;
typedef int T;

class Node
{
public:
	T coef;  //系数
	T exp;  //指数
	Node* next;  //指针域
};

class Link
{
public:
	Link();
	~Link();
	void CreatLink();
	void ShowLink();
	void AddLink(Link& L1, Link& L2);
	void SubLink(Link& L1, Link& L2);
	void MulLink(Link& L1, Link& L2);
	void SortLink();     //按指数排序

private:
	Node* L;
	T length;
};

Link::Link()
{
	L = new Node;
	L->next = NULL;
	length = 0;
}

void Link::CreatLink()
{
	Node* pnew = new Node;
	pnew->next = NULL;
	cout << "输入系数：" << " "; cin >> pnew->coef;
	cout << "输入指数：" << " "; cin >> pnew->exp;
	Node* ptemp = L;
	while (ptemp->next) {
		ptemp = ptemp->next;
	}
	ptemp->next = pnew;
	length++;
}

void Link::ShowLink()
{
	Node* ptemp =L ;
	cout << "系数和指数分别为：" << " ";
	while (ptemp->next) {
		ptemp = ptemp->next;
		cout << ptemp->coef << "  ";
		cout << ptemp->exp << "  ；";
	}
	cout << endl;
}

void Link::AddLink(Link& L1, Link& L2)
{
	Node* t = L1.L;
	Node* ptemp = L1.L->next; Node* qtemp = L2.L->next;
	while (ptemp && qtemp) {
		if (ptemp->exp < qtemp->exp) {
			t->next = ptemp;
			t = ptemp;
			ptemp = ptemp->next;
		}
		else if (ptemp->exp > qtemp->exp) {
			t->next = qtemp;
			t = qtemp;
			qtemp = qtemp->next;
		}
		else {
			ptemp->coef += qtemp->coef;
			if (ptemp->coef) {//coef不等于0时
				t->next = ptemp;  //将修改后的ptemp当前节点链在t之后
				t = ptemp;             //t指向ptemp
				ptemp = ptemp->next;  //ptemp指向下一项
				qtemp = qtemp->next;//qtemp后移
			}
			else {
				Node* r = ptemp; 
				ptemp = ptemp->next;
				delete r; r = NULL;
				qtemp = qtemp->next;
			}
		}
	}
	if (!ptemp) {
		t->next = qtemp;
	}
	if (!qtemp) {
		t->next = ptemp;
	}
}

void Link::SubLink(Link& L1, Link& L2)
{
	Node* t = L1.L;
	Node* ptemp = L1.L->next; Node* qtemp = L2.L->next;
	while (ptemp && qtemp) {
		if (ptemp->exp < qtemp->exp) {
			t->next = ptemp;
			t = ptemp;
			ptemp = ptemp->next;
		}
		else if (ptemp->exp > qtemp->exp) {
			t->next = qtemp;
			t = qtemp;
			qtemp = qtemp->next;
		}
		else {
			ptemp->coef -= qtemp->coef;
			if (ptemp->coef) {//coef不等于0时
				t->next = ptemp;  //将修改后的ptemp当前节点链在t之后
				t = ptemp;             //t指向ptemp
				ptemp = ptemp->next;  //ptemp指向下一项
				qtemp = qtemp->next;//qtemp后移
			}
			else {
				Node* r = ptemp;
				ptemp = ptemp->next;
				delete r; r = NULL;
				qtemp = qtemp->next;
			}
		}
	}
	if (!ptemp) {
		t->next = qtemp;
	}
	if (!qtemp) {
		t->next = ptemp;
	}
}

void Link::MulLink(Link& L1, Link& L2)
{
	Node* ptemp = L1.L; Node* qtemp = L2.L;
	Link Lnew;  Node* tnew = Lnew.L;
	while (ptemp->next) {
		ptemp = ptemp->next;
		while (qtemp->next) {
			qtemp = qtemp->next;
			Node* pnew = new Node;
			pnew->next = NULL;
			pnew->exp = ptemp->exp + qtemp->exp;
			pnew->coef = (ptemp->coef) * (qtemp->coef);
			tnew->next = pnew; tnew = tnew->next;
		}
		qtemp = L2.L;
	}
	Lnew.SortLink();
	Lnew.ShowLink();
}

void Link::SortLink()
{
	Node* ptemp = L->next; 
	while (ptemp) {
		Node* qtemp = ptemp->next;
		while (qtemp) {
			if (ptemp->exp < qtemp->exp) {
				qtemp = qtemp->next;
			}
			else if (ptemp->exp > qtemp->exp) {
				int c = 0; int e = 0;
				c = ptemp->coef; e = ptemp->exp;
				ptemp->coef = qtemp->coef;
				ptemp->exp = qtemp->exp;
				qtemp->coef = c; qtemp->exp = e;
				qtemp = qtemp->next;
			}
			else {
				ptemp->coef += qtemp->coef;
				Node* pnew = qtemp;
				qtemp = qtemp->next;
				ptemp->next = qtemp;
				delete pnew; pnew = NULL;
			}
		}
		ptemp = ptemp->next;
	}
}

Link::~Link()
{
	Node* ptemp = L->next;
	while (ptemp) {
		L->next = ptemp->next;
		ptemp = L->next;
	}
	length = 0;
}

int main()
{
	Link s1, s2;
	s1.CreatLink();
	s1.CreatLink();
	s1.CreatLink();
	s1.ShowLink();
	s1.SortLink();
	s1.ShowLink();

	s2.CreatLink();
	s2.CreatLink();
	s2.SortLink();
	s2.ShowLink();

	s1.MulLink(s1, s2);

	system("pause");
	return 0;
}