两个多项式相加算法（链表实现）

来源：数据结构期中考试补充题

注：该代码测试数据较少，吃过晚饭有时间再测试下改改bug QAQ

//多项式相加：
#include <iostream>
using namespace std;

class Node {//项的定义
	
public:
	int a;
	int b;
	Node* next;
	Node(int aa, int bb) {
		a = aa;
		b = bb;
		next = NULL;;
	}
};
class List{
public:
	List() {
		Creat();
	}
	Node* head;
	void Creat();
};
void List::Creat() {
	int num1, num2;
	cout << "请输入该链表元素个数：" << endl;
	int num;
	cin >> num;
	cout << "请输入组合（空格分隔即可）" << endl;
	head = new Node(1, 1);
	Node* p = head;
	while (num--) { //创建一个单链表；
		cin >> num1 >> num2;
		Node* s = new Node(num1, num2);
		p->next = s; 
		p = s;
	}
	p->next = NULL;
}
Node* Add(List &A,List &B) {
	Node* pc = A.head;
	Node* pa = A.head->next;
	Node* pb = B.head->next;
	while (pa && pb) {
		int num1 = pa->b;
		int num2 = pb->b;
		if (num1 == num2) {
			//如果指数相同，加和为0
			if (pa->a + pb->a == 0) {
				Node* p1 = pa;
				pa = pa->next;
				Node* p2 = pb;
				pb = pb->next;
				delete p1, p2;
			}
			//指数相同，加和不为0
			else {
				pa->a = pa->a + pb->a;
				pc->next = pa;
				pc = pa;
				Node* p = pb;
				pb = pb->next;
				delete(p);
			}
		}
		//如果不相同，将指数小的接入新链表：
		else {
			if (num1 < num2) {
				pc->next = pa;
				pc = pa;
				pa = pa->next;
			}
			else {
				pc->next = pb;
				pc = pb;
				pb = pb->next;
			}
		}
	}
	if (pa == NULL) {
		pc->next = pb;
	}
	else pc->next = pa;
	return A.head;
}
//表的定义：
int main() {
	cout << "创建链表A：" << endl;
	List A;
	cout << "创建链表B：" << endl;
	List B;
	Node* c=Add(A, B);
	Node* C = c->next;
	while (C != NULL) {
		cout << C->a << "*" << "X" << C->b << ' ';
		C = C->next;
	}
	return 0;
}

欢迎各位的讨论交流和批评指正:)