#include<stdio.h>
#include<stdlib.h>
typedef struct List     //构建结构体
{ int coef;
int exp;
struct List *next;
}Node;
int Compare(int a,int b)      //比较指数大小
{
if(a>b)
return 1;
else {if(a=b)
return 0;
else
return -1;
}
}
void Attach(int coef,int exp,Node *Rear)   //将系数大的项连接到新链表的后面
{   Node *P;
P=(Node*)malloc(sizeof (Node));
P->coef=coef;
P->exp=exp;
Rear->next=P;
Rear=P;
}
Node Add(Node *p1,Node *p2)    //保存有多项式系数和指数的两个链表相加，返回 头指针p3（这一步出现题中所说错误）
{
Node *p3,*rear3,*temp3;
int sum=0;
rear3=(Node*)malloc(sizeof (Node));
p3=rear3;
while(p1&&p2)
{switch(Compare(p1->exp,p2->exp))
{  case 1:
Attach(p1->coef,p1->exp,rear3);
p1=p1->next;
break;
case -1:
Attach(p2->coef,p2->exp,rear3);
p2=p2->next;
break;
case 0:
sum=p1->coef+p2->coef;
if(sum!=0)
Attach(sum,p1->exp,rear3);
break;
}}
for(;p1;p1=p1->next) Attach(p1->coef,p1->exp,rear3);
for(;p2;p2=p2->next) Attach(p2->coef,p2->exp,rear3);
rear3->next=NULL;
temp3=p3;
p3=p3->next;
free(temp3);
return *p3;
}
int main()
{   int N1=0,N2=0;
int n1=0;int n2=0;
Node *p1,*p2;
Node *rear1,*rear2;
Node *temp1,*temp2;
Node *temp;
Node *p;
p1=rear1=(Node*)malloc(sizeof (Node));
rear1=NULL;
p1->next=rear1;
temp1=p1;
printf(“请输入第一个多项式的非零项数N1：”);
scanf(“%d”,&N1);
printf(“请输入每个非零项的系数和指数，以空格隔开：”);
while(n1<N1)
{  rear1=(Node*)malloc(sizeof (Node));
scanf(“%d”,&rear1->coef);
scanf(“%d”,&rear1->exp);
rear1->next=NULL;
temp1->next=rear1;
temp1=temp1->next;
n1++;
}
temp=p1;
p1=p1->next;
free(temp);
p2=rear2=(Node*)malloc(sizeof (Node));
rear2=NULL;
p2->next=rear2;
temp2=p2;
printf(“请输入第一个多项式的非零项数N2：”);
scanf(“%d”,&N2);
printf(“请输入每个非零项的系数和指数，以空格隔开：”);
while(n2<N2)
{  rear2=(Node*)malloc(sizeof (Node));
scanf(“%d”,&rear2->coef);
scanf(“%d”,&rear2->exp);
rear2->next=NULL;
temp2->next=rear2;
temp2=temp2->next;
n2++;
}
temp=p2;
p2=p2->next;
free(temp);
n1=0;
while(n1<N1)
{
printf(“%d\n”,p1->coef);
p1=p1->next;
n1++;
}
n2=0;
while(n2<N2)
{
printf(“%d\n”,p2->coef);
p2=p2->next;
n2++;
}
p=(Node*)malloc(sizeof (Node));
*p=Add(p1,p2);
printf(“两个多项式相加后的系数和指数为：”);
while(p)
{
printf(“%d %d “,p->coef,p->exp);
p=p->next;
}
return 0;
}