#include?
using?namespace?std;
struct?Node
{
	int?index;
	double?co;
	Node?*next;
};
????Node*?head=new?Node;

void?sort（Node?*headint?n）//n代表個數
{
???while（n>1）
???{
?????Node?*p=head->next;Node?*q=head;
?????bool?exchange=false;
???????while（p->next）
	???{
????????if（p->indexnext->index）
		{
??????????exchange=true;
??????????q->next=p->next;
??????????p->next=p->next->next;
??????????q->next->next=p;
??????????q=q->next;
		}
????????else
		{
?????????q=p;p=p->next;
		}
	???}
?????if（exchange=false）break;
?????n--;
???}
???Node?*p*q;
???for（p=headq=head->next;q&&q->next;q=q->next）
???{
????if（p->next->index!=q->next->index）
	{
??????p=p->next;
??????continue;
	}
????if（p->next->co+q->next->co==0）
	{
?????Node?*ss=p;
?????q=q->next->next;
?????p->next=q;
?????delete?ss->next->next;
?????delete?ss->next;
	}
????else?
	{
?????q->co+=q->next->co;
?????q=q->next->next;
?????p=p->next;
?????Node?*ss=p->next;
?????p->next=q;
?????delete?ss;
	}
???}
}
void?build（Node?*&headint?n）//建立多項式
{
	int?i=1;
	cout<<“請輸入多項式的系數及指數“;
	Node?*p=head;
	while（i<=n）
	{
????????p->next=new?Node;
????????p=p->next;
		cin>>p->co>>p->index;
		i++;
	}
	p->next=0;
}
void?change（Node?*headint?n）//多項式系數取反
{???
	Node?*p=head;
	while（p->ne