02-线性结构2 一元多项式的乘法与加法运算

#include <cstdio>
#include <cstdlib>
using namespace std;

typedef struct PolyNode *Polynomial; //
struct PolyNode{    //系数指数
    int coef;
    int expon;
    Polynomial link;
};
void Add(int c,int e,Polynomial * rear)
{
    Polynomial p= new PolyNode;
    p->coef=c;  p->expon=e;
    p->link= NULL;
    (*rear)->link = p;
    *rear= p;
}
Polynomial Mult(Polynomial p1 ,Polynomial p2)
{
    Polynomial p = new PolyNode,t1=p1,t2=p2,t;    p->link=NULL;
    Polynomial rear = p; int e,c;
    if(!p1||!p2) return NULL;
    while(t2)
    {
        if(t2->coef*t1->coef!=0)
            Add(t2->coef*t1->coef,t1->expon+t2->expon,&rear);
        t2=t2->link;
    }
    t1=t1->link;
    while(t1){
        rear=p;t2=p2;
        while(t2){
            e=t1->expon+t2->expon;
            c=t1->coef*t2->coef;
            while(rear->link&&rear->link->expon>e)
                rear=rear->link;
            if(rear->link&&rear->link->expon==e){
                if(rear->link->coef+c)
                    rear->link->coef+=c;
                else
                {
                    t=rear->link;
                    rear->link=t->link;
                    delete t;
                }
            }
            else{
                t=new PolyNode;
                t->coef=c;t->expon=e;
                t->link = rear->link;
                rear->link=t;  rear=rear->link;
            }
            t2=t2->link;
        }
        t1=t1->link;
    }
    t2=p;p=p->link;delete t2;
    return p;

}
Polynomial ReadPoly()
{
    Polynomial P,rear,t;
    P= new PolyNode;
    P->link=NULL;
    rear=P;
    int n,c,e;
    scanf("%d",&n);
    while(n--){
        scanf("%d%d",&c,&e);
        Add(c,e,&rear);
    }
    t=P;
    P=P->link;
    delete t;
    return P;
}
void print(Polynomial p)
{
    int flag=1;
    if(!p)
        printf("0 0");
    while(p){
        if(flag){
            printf("%d %d",p->coef,p->expon);
            flag=0;
        }
        else{
            printf(" %d %d",p->coef,p->expon);
        }
        p=p->link;
    }
    printf("\n");
}
Polynomial ADD(Polynomial p1,Polynomial p2)
{
    Polynomial p,t1=p1,t2=p2,rear;
    p = new PolyNode;
    p->link =NULL;
    rear = p;
    while(t1&&t2)
    {
        if(t1->expon==t2->expon)
        {
            int s = t1->coef+t2->coef;
            if(s!=0)
            {
                Add(s,t1->expon,&rear);
            }
            t1=t1->link;
            t2=t2->link;
        }
        else
        {
            if(t1->expon>t2->expon)
            {
                Add(t1->coef,t1->expon,&rear);
                t1=t1->link;
            }
            else
            {
                Add(t2->coef,t2->expon,&rear);
                t2=t2->link;
            }
        }
    }
    while(t2)
    {
        Add(t2->coef,t2->expon,&rear);
        t2=t2->link;
    }
    while(t1)
    {
        Add(t1->coef,t1->expon,&rear);
        t1=t1->link;
    }
    t1=p;
    p=p->link;
    delete t1;
    return p;
}
int main(){
    //freopen("in.txt","r",stdin);
    Polynomial p1,p2,pp,ps;
    p1=ReadPoly();
    p2=ReadPoly();
    pp=Mult(p1,p2);
    print(pp);
    ps=ADD(p1,p2);
    print(ps);


    return 0;
}