C语言实现多项式的加减乘运算

#include<stdio.h>
#include<malloc.h> //include head file

typedef struct Polynode {
int coef;
int exp;
struct Polynode *next;
}Polynode; // define struction

int poly_Init(Polynode **head) {
*head = (Polynode*)malloc(sizeof(Polynode));
if (*head == NULL)
return 0;
(*head)->coef = 0;
(*head)->exp = 0;
(*head)->next = NULL;
return 1;
} // Initial the head pointer and evaluation

int poly_sortNode(Polynode *head, int coef, int exp) {
Polynode *rear, *s, *p;
rear = head;
s = rear->next;
while (s != NULL && s->exp < exp) {
rear = s;
s = s->next;
}
if (s != NULL && s->exp == exp) {
s->coef += coef;
}

else {
p = (Polynode*)malloc(sizeof(Polynode));
if (p == NULL)
return 0;
p->coef = coef;
p->exp = exp;
p->next = rear->next;
rear->next = p;
}
return 1;
} // sort and add the like terms of multinomial

Polynode* polycreate( /* Polynode *head */ ) {
Polynode *h, *rear, *s;
int c, e;
if (!poly_Init(&h))
return NULL;
printf("Please Input coef and exp(end with coef equal to 0):\n");
scanf("%d%d", &c, &e); /* 键入多项式的系数和指数项 */
while (c != 0) /* 若c=0，则代表多项式的输入结束 */ {
poly_sortNode(h, c, e);
scanf("%d%d", &c, &e);
}
return(h);
} // create the multinomial

Polynode* polylist_add(Polynode *head1, Polynode *head2) {
int sum;
Polynode *r;
Polynode *p = head1->next, *q = head2->next;