02-线性结构2 一元多项式的乘法与加法运算

这道习题有点难。。。自己实现了一遍，还是有小的问题存在。无法达到题目要求的格式。但是已经可以计算出正确结果了。如果有发现问题的话请大家多多指正。谢谢！！！

#include <stdio.h>#include <stdlib.h>typedef struct SNode* Polynomial;struct SNode {    int coef;    int exp;    struct SNode* next;};int Compare(int a, int b);void Attach(int coef, int exp, Polynomial *prear);Polynomial ReadPoly();void PrintPoly(Polynomial P);Polynomial AddPoly(Polynomial P1, Polynomial P2);Polynomial MultPoly(Polynomial P1, Polynomial P2);int Compare(int a, int b){    if (a > b)        return 1;    else if (a < b)        return -1;    else        return 0;}void Attach(int coef, int exp, Polynomial *prear){    Polynomial P;    P = (Polynomial)malloc(sizeof(struct SNode));    P->coef = coef;    P->exp = exp;    P->next = NULL;    /*将P插入到当前结果表达式尾项的最后面*/    (*prear)->next = P;    (*prear) = P;}Polynomial ReadPoly(){    Polynomial P, rear, temp;    int N;    P = (Polynomial)malloc(sizeof(struct SNode));    rear = P;    P->next = NULL;     int coef, exp;    scanf("%d", &N);    while (N--)    {        scanf("%d %d", &coef, &exp);        Attach(coef, exp, &rear);    }    temp = P;    P = P->next;    free(temp);    return P;}void PrintPoly(Polynomial P){    int flag = 0;    if (!P)        printf("0 0\n");while (P)    {        if (!flag)            flag = 1;        else            printf(" ");        if (P->coef != 0)        {            printf("%d %d", P->coef, P->exp);            P = P->next;        }        else            P = P->next;    }    printf("\n");}Polynomial AddPoly(Polynomial P1, Polynomial P2){    Polynomial P, rear, temp;    P = (Polynomial)malloc(sizeof(struct SNode));    P->next = NULL;    rear = P;    while (P1&&P2)    {        switch (Compare(P1->exp, P2->exp))        {        case 1:            Attach(P1->coef, P1->exp, &rear);            P1 = P1->next;            break;        case -1:            Attach(P2->coef, P2->exp, &rear);            P2 = P2->next;            break;        case 0:            if(P1->coef + P2->coef)            Attach(P1->coef + P2->coef, P2->exp, &rear);            P1 = P1->next;            P2 = P2->next;            break;        }    }    for (; P1; P1=P1->next)        Attach(P1->coef, P1->exp, &rear);    for (; P2;P2= P2->next)        Attach(P2->coef, P2->exp, &rear);    rear->next = NULL;    temp = P;    P = P->next;    free(temp);    return P;}Polynomial MultPoly(Polynomial P1, Polynomial P2){    Polynomial P, rear, temp,temp1,temp2;    Polynomial MultP;    MultP = (Polynomial)malloc(sizeof(struct SNode));    MultP->coef = 0;    MultP->exp = 0;    MultP->next = NULL;    P = (Polynomial)malloc(sizeof(struct SNode));    rear = P;    temp2 = P;    P->next = NULL;    temp1 = P2;    for (; P1; P1 = P1->next)     {        while (temp1) {            Attach(P1->coef*temp1->coef, P1->exp + temp1->exp, &rear);            temp1 = temp1->next;        }        rear->next = NULL;        temp = temp2;        temp2 = temp2->next;        MultP = AddPoly(MultP, temp2);        temp1 = P2;        rear = P;        temp2 = P;    }    return MultP;}int main(void){    Polynomial P1, P2, P,P0;    P1 = ReadPoly();    P2 = ReadPoly();    P0 = MultPoly(P1, P2);    PrintPoly(P0);    P = AddPoly(P1, P2);    PrintPoly(P);}

最后的多项式乘法函数写的风格不够简明，不懂的可以问我。但个人感觉好像比我看到的好多代码都简单些。希望大家批评指正。