多项式加法和除法.cpp

#include <stdio.h>
#include <stdlib.h>
typedef struct PolyNode *Polynomial;
struct PolyNode 
{
    int coef;
    int expon;
    Polynomial link;
};

void Attach(int c, int e, Polynomial *Rear)
{
    Polynomial P;
    P = (Polynomial)malloc(sizeof(struct PolyNode));
    P -> coef = c;
    P -> expon = e;
    P->link = NULL;
    (*Rear)->link = P;
    *Rear = P;
}

Polynomial ReadPoly()
{
    Polynomial P,Rear, t;
    int c, e, N;

    scanf("%d", &N);// num of polynomial
    P = (Polynomial)malloc(sizeof(struct PolyNode)); // build empty node at first
    P ->link = NULL;
    Rear = P;
    while( N--)
    {
        scanf("%d %d", &c, &e);
        Attach(c, e, &Rear);
    }
    t = P; P = P->link;
    free(t);

    return P;
}

void PrintPoly( Polynomial P)
{
    int flag = 0;
    if(!P)
    {
        printf("0 0\n");
        return ;
    }
    while(P)
    {
        if(!flag)
            flag = 1;
        else
            printf(" ");
        printf("%d %d",P->coef, P -> expon);
        P = P->link;

    }
    printf("\n");
}

Polynomial Add(Polynomial P1, Polynomial P2)
{
    Polynomial P, Rear, t1, t2,temp;
    t1 = P1; t2 = P2;
    P = (Polynomial)malloc(sizeof(struct PolyNode)); // build empty node at first
    Rear = P;
    while(t1 && t2)
    {
        if (t1 -> expon == t2->expon)
        {
            if(t1->coef+t2->coef != 0)
            {
                Attach(t1->coef+t2->coef, t1->expon, &Rear);  
            }
            t1 = t1 ->link;
            t2 = t2 ->link;  
        }
        else if(t1 -> expon > t2->expon)
        {
            Attach(t1->coef, t1->expon, &Rear);
            t1 = t1 ->link;
        }
        else
        {
            Attach(t2->coef, t2->expon, &Rear);
            t2 = t2 ->link;
        }

    }
    while(t1)
    {
        Attach(t1->coef, t1->expon, &Rear);  
        t1 = t1 ->link;
    }
    while(t2)
    {
        Attach(t2->coef, t2->expon, &Rear);  
        t2 = t2 ->link;
    }
    Rear->link = NULL;
    temp = P;
    P = P->link;
    free(temp);
    return P;
}

Polynomial Mult(Polynomial P1, Polynomial P2)
{
    Polynomial P, Rear, t1, t2, t;
    int c, e;

    if (!P1 || !P2)
        return NULL;

    t1 = P1; t2 = P2;
    P = (Polynomial)malloc(sizeof(struct PolyNode)); // build empty node at first
    Rear = P;
    while(t2)
    {
        Attach(t1->coef*t2->coef, t1->expon + t2->expon, &Rear);
        t2 = t2 -> link;
    }

    t1 = t1 -> link;
    while(t1)
    {
        t2 = P2;Rear = P;
        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;
                    free(t);
                }
            }
            else
            {
                t = (Polynomial)malloc(sizeof(struct 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; free(t2);
    return P;
}

int main()
{
    Polynomial P1, P2, PP, PS;
    P1 = ReadPoly();
    P2 = ReadPoly();
    PP = Mult(P1,P2);
    PrintPoly(PP);
    PS = Add(P1,P2);
    PrintPoly(PS);

    return 0;
}