PAT 02-线性结构2 一元多项式的乘法与加法运算 (20分)

设计函数分别求两个一元多项式的乘积与和。

输入格式:

输入分2行，每行分别先给出多项式非零项的个数，再以指数递降方式输入一个多项式非零项系数和指数（绝对值均为不超过1000的整数）。数字间以空格分隔。

输出格式:

输出分2行，分别以指数递降方式输出乘积多项式以及和多项式非零项的系数和指数。数字间以空格分隔，但结尾不能有多余空格。零多项式应输出0 0。

输入样例:

4 3 4 -5 2  6 1  -2 0
3 5 20  -7 4  3 1

输出样例:

15 24 -25 22 30 21 -10 20 -21 8 35 6 -33 5 14 4 -15 3 18 2 -6 1
5 20 -4 4 -5 2 9 1 -2 0
================================================================================第一次code:

 #include <stdio.h>
 #include <stdlib.h>

 /* run this program using the console pauser or add your own getch, system("pause") or input loop */

 /*
     定义链表结构
 */
 typedef struct Node *Ptrnomial;
 typedef Ptrnomial LinkList;  //头结点
 typedef Ptrnomial Position;//中间节点
 struct Node
 {
     int coef;  /*系数*/
     int expon;  /*指数*/
     Position link;
 };

 LinkList Read();
 void Print(LinkList L);
 LinkList Multiplication(LinkList L1,LinkList L2);    /*乘法*/
 LinkList Add(LinkList L1,LinkList L2);  /*加法*/

 int main(void)
 {
     LinkList L1,L2,L3,L4;
     L1 = Read();
     L2 = Read();
     L3 = Add(L1,L2);
     L4 = Multiplication(L1,L2);
     Print(L4);
     printf("\n");
     Print(L3);
     ;
 }
 LinkList Read()
 {
     int n,c,e;
     scanf("%d",&n);
     LinkList L,Rear,p;
     L = (Ptrnomial)malloc(sizeof(struct Node));
     Rear = L;
     while(n--)
     {
         p = (Ptrnomial)malloc(sizeof(struct Node));
         scanf("%d %d",&c,&e);
         p->coef = c;
         p->expon = e;
         Rear->link = p;
         Rear = p;
     }
     Rear->link = NULL;
     return L;
 }
 void Print(LinkList L)
 {
     LinkList L1;
     L1 = L->link;
     ;
     if( !L1 )    /*意思是L1为空时*/
     {
         printf("0 0");
         return ;
     }
     while( L1 )  /*意思是L1不为空时*/
     {
         if(!flag)
         {
             flag = ;
         }
         else
         {
             printf(" ");
         }
         printf("%d %d",L1->coef,L1->expon);
         L1 = L1->link;
     }
 }
 /*多项式相乘*/
 LinkList Multiplication(LinkList L1,LinkList L2)
 {
     Position l1,l2;
     LinkList l,temp,r,p;
     l1 = L1->link;
     l2 = L2->link;
     l = (struct Node*)malloc(sizeof(struct Node));
     l->link = NULL;
     if( !l1 || !l2)
     {
         return l;
     }
     while( l1 )
     {
         temp = (struct Node*)malloc(sizeof(struct Node));
         r = temp;
         l2 = L2->link;
         while( l2 )
         {
             p = (struct Node*)malloc(sizeof(struct Node));
             p->expon = l1->expon + l2->expon;
             p->coef = l1->coef * l2->coef;
             l2 = l2->link;
             r->link = p;
             r = p;
         }
         r->link = NULL;
         l = Add(l,temp);
         l1 = l1->link;
     }
     return l;
 }
 /*多项式相加*/
 LinkList Add(LinkList L1,LinkList L2)
 {
     int sum;
     Position l1, l2;
     LinkList l,r,p;
     l1 = L1->link;
     l2 = L2->link;
     l = (struct Node*)malloc(sizeof(struct Node));
     r = l;
     while( l1 && l2)
     {
         /*当两个多项式都存在时*/
         p = (struct Node*)malloc(sizeof(struct Node));
         if(l1->expon == l2->expon)
         {
             /*系数相等时*/
             sum = l1->coef + l2->coef;
             if( sum )
             {
                 p->expon = l1->expon;
                 p->coef = sum;
                 r->link = p;
                 r = p;
             }
             l2 = l2->link;
             l1 = l1->link;
         }
         else if(l1->expon < l2->expon)
         {
             p->expon = l2->expon;
             p->coef = l2->coef;
             l2 = l2->link;
             r->link = p;
             r = p;
         }
         else
         {
             p->expon = l1->expon;
             p->coef = l1->coef;
             l1 = l1->link;
             r->link = p;
             r = p;
         }
     }
     if( l2 == NULL)
     {
         while( l1 )
         {
             p = (struct Node*)malloc(sizeof(struct Node));
             p->expon = l1->expon;
             p->coef = l1->coef;
             l1 = l1->link;
             r->link = p;
             r =p ;
         }
     }
     if( l1 == NULL)
     {
         while( l2 )
         {
             p = (struct Node*)malloc(sizeof(struct Node));
             p->expon = l2->expon;
             p->coef = l2->coef;
             l2 = l2->link;
             r->link = p;
             r =p ;
         }
     }
     r->link = NULL;
     return l;
 }