用c语言实现两个一元多项式的加和

#include <stdio.h>
#include <stdlib.h>

struct node{
    float coef; //系数
    int expn; //指数
    struct node *next; //指向下一个节点的指针
};

void create_polynomial(struct node **head, int n)
{
    struct node *tail = *head;
    for(int i = 0; i < n; i++){
        struct node *p = (struct node *)malloc(sizeof(struct node));
        scanf("%f%d", &p->coef, &p->expn);
        p->next = NULL;
        if(*head == NULL){
            *head = p;
            tail = p;
        }
        else{
            tail->next = p;
            tail = p;
        }
    }
}

void print_polynomial(struct node *head)
{
    if(head == NULL){
        printf("0 0\n");
        return;
    }
    while(head != NULL){
        printf("%.1f %d", head->coef, head->expn);
        head = head->next;
        if(head != NULL){
            printf(" ");
        }
    }
    printf("\n");
}

void add_polynomial(struct node *p1, struct node *p2, struct node **p3)
{
    while(p1 != NULL && p2 != NULL){
        if(p1->expn > p2->expn){
            struct node *p = (struct node *)malloc(sizeof(struct node));
            p->coef = p1->coef;
            p->expn = p1->expn;
            p->next = NULL;
            if(*p3 == NULL){
                *p3 = p;
            }
            else{
                struct node *tail = *p3;
                while(tail->next != NULL){
                    tail = tail->next;
                }
                tail->next = p;
            }
            p1 = p1->next;
        }
        else if(p1->expn < p2->expn){
            struct node *p = (struct node *)malloc(sizeof(struct node));
            p->coef = p2->coef;
            p->expn = p2->expn;
            p->next = NULL;
            if(*p3 == NULL){
                *p3 = p;
            }
            else{
                struct node *tail = *p3;
                while(tail->next != NULL){
                    tail = tail->next;
                }
                tail->next = p;
            }
            p2 = p2->next;
        }
        else{
            struct node *p = (struct node *)malloc(sizeof(struct node));
            p->coef = p1->coef + p2->coef;
            p->expn = p1->expn;
            p->next = NULL;
            if(*p3 == NULL){
                *p3 = p;
            }
            else{
                struct node *tail = *p3;
                while(tail->next != NULL){
                    tail = tail->next;
                }
                tail->next = p;
            }
            p1 = p1->next;
            p2 = p2->next;
        }
    }
    while(p1 != NULL){
        struct node *p = (struct node *)malloc(sizeof(struct node));
        p->coef = p1->coef;
        p->expn = p1->expn;
        p->next = NULL;
        if(*p3 == NULL){
            *p3 = p;
        }
        else{
            struct node *tail = *p3;
            while(tail->next != NULL){
                tail = tail->next;
            }
            tail->next = p;
        }
        p1 = p1->next;
    }
    while(p2 != NULL){
        struct node *p = (struct node *)malloc(sizeof(struct node));
        p->coef = p2->coef;
        p->expn = p2->expn;
        p->next = NULL;
        if(*p3 == NULL){
            *p3 = p;
        }
        else{
            struct node *tail = *p3;
            while(tail->next != NULL){
                tail = tail->next;
            }
            tail->next = p;
        }
        p2 = p2->next;
    }
}

int main()
{
    struct node *head1 = NULL;
    struct node *head2 = NULL;
    struct node *head3 = NULL;
    int n1, n2;
    scanf("%d", &n1);
    create_polynomial(&head1, n1);
    scanf("%d", &n2);
    create_polynomial(&head2, n2);
    add_polynomial(head1, head2, &head3);
    print_polynomial(head3);
    return 0;
}