1 #include <iostream>  2 #include<stdlib.h>  3   4 using namespace std;  5   6   7 #define MAXSIZE 20  8   9 typedef struct LNode 10 { 11     int coef;//系数 12     int expn;//指数 13     struct LNode *next; 14 }LNode,*LinkList; 15  16  17 int CreateList_L(LinkList &L,int n) 18 { 19     LinkList p,q; 20     for(int i=0;i<n;i++) 21     { 22          p=(LinkList)malloc(sizeof(LNode)); 23          cout<<"输入元素系数："; 24          cin>>p->coef; 25          cout<<"输入元素指数："; 26          cin>>p->expn; 27          if(i==0)L=p; 28          else q->next=p; 29          q=p; 30          p->next=NULL; 31     } 32    return 0; 33 } 34  35  36 int LengthPolyn(LinkList L)//判断多项式的项数 37 { 38     int s=0; 39     while(L) 40     { 41         s++; 42         L=L->next; 43     } 44     return s; 45 } 46  47  48 int CopyList_L(LinkList La,LinkList &Lb)//开辟一段和La指向的空间一样的新的空间，并把La中各元素的值依次复制到Lb中 49 { 50     LinkList p,q,pa=La; 51     int n=LengthPolyn(La); 52     for(int i=0;i<n;i++) 53     { 54          p=(LinkList)malloc(sizeof(LNode)); 55          p->coef=pa->coef; 56          p->expn=pa->expn; 57          if(i==0)Lb=p; 58          else q->next=p; 59          q=p; 60          p->next=NULL; 61          pa=pa->next; 62     } 63    return 0; 64 } 65  66  67  68 int Display_L(LinkList L) 69 { 70     cout<<"f(x)="<<L->coef; 71     if(L->expn)cout<<"*"<<"x^"<<L->expn; 72     L=L->next; 73     while(L) 74     { 75         if(L->coef>0) 76         { 77             cout<<"+"; 78             cout<<L->coef<<"*"<<"x^"<<L->expn; 79         } 80         else cout<<L->coef<<"*"<<"x^"<<L->expn; 81         L=L->next; 82     } 83     return 0; 84 } 85  86  87  88 int AddPolyn(LinkList La,LinkList Lb,LinkList &Lc) 89 { 90     LinkList pa,pb,p; 91     int k=1; 92     pa=La;pb=Lb; 93     //确定“和多项式”的头结点 94     while(k) 95     { 96          if(pa->expn<pb->expn){p=Lc=pa;pa=pa->next;k=0;} 97          else if(pa->expn>pb->expn){p=Lc=pb;pb=pb->next;k=0;} 98          else 99          {100              pa->coef+=pb->coef;101              if(pa->coef)102              {103                   p=Lc=pa;104                   pa=pa->next;105                   k=0;106              }107              else108              {109                  pa=pa->next;110                  pb=pb->next;111                  if(!pa||!pb) break;112              }113          }114     }115     if(!pb&&pa){p=Lc=pa;pa=pa->next;}116     if(!pa&&pb){p=Lc=pb;pb=pb->next;}117     if(!pa&&!pb) Lc=NULL;118     //确定接下来的节点119     while(pa&&pb)120     {121         if(pa->expn<pb->expn){p->next=pa;p=pa;pa=pa->next;}122         else if(pa->expn>pb->expn){p->next=pb;p=pb;pb=pb->next;}123         else124         {125             pa->coef+=pb->coef;126             if(pa->coef)127             {128                   p->next=pa;129                   p=pa;130                   pa=pa->next;131                   pb=pb->next;132             }133             else134             {135                   pa=pa->next;136                   pb=pb->next;137             }138 139         }140     }141     while(!pb&&pa)142     {143         p->next=pa;144         p=pa;145         pa=pa->next;146     }147     while(!pa&&pb)148     {149         p->next=pb;150         p=pb;151         pb=pb->next;152     }153     return 0;154 }155 156 157 158 int MultiplyPolyn(LinkList La,LinkList Lb,LinkList &Lc)//La指向的多项式乘以Lb指向的多项式159 {160     LinkList pa,pb=Lb,l;161     int i=0,j,n;162     LNode *L[MAXSIZE];//指针数组，Lb至多MAXSIZE项！163     while(pb)164     {165         CopyList_L(La,L[i]);166         pa=L[i];167         while(pa)168         {169             pa->coef*=pb->coef;170             pa->expn+=pb->expn;171             pa=pa->next;172         }173         pb=pb->next;174         i++;175     }176     n=LengthPolyn(Lb);177     AddPolyn(L[0],L[1],Lc);178     for(j=2;j<n;j++)179     {180         AddPolyn(L[j],l,Lc);181         l=Lc;182     }183     return 0;184 }185 186 187 188 int main()189 {190     LinkList La,Lb,Lc;191     int m,n;192     cout<<"请输入La中的元素个数：";193     cin>>m;194     CreateList_L(La,m);195     cout<<"请输入Lb中的元素个数：";196     cin>>n;197     CreateList_L(Lb,n);198     MultiplyPolyn(La,Lb,Lc);199     Display_L(Lc);200     return 0;201 }