基于链式存储结构的图书信息表的输出C语言代码

以下是基于链式存储结构的图书信息表的输出C语言代码：

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

typedef struct book {
    char id[20];
    char name[50];
    float price;
    struct book *next;
} Book;

int main() {
    int n = 0;
    float sum = 0, avg = 0;
    Book *head = NULL, *p = NULL, *q = NULL;

    // 输入图书信息
    while (1) {
        p = (Book *)malloc(sizeof(Book));
        scanf("%s", p->id);
        if (strcmp(p->id, "0") == 0) {
            free(p);
            break;
        }
        scanf("%s%f", p->name, &p->price);
        sum += p->price;
        n++;
        if (head == NULL) {
            head = p;
        } else {
            q->next = p;
        }
        q = p;
    }

    // 计算平均价格
    avg = sum / n;

    // 修改价格并输出图书信息
    p = head;
    while (p != NULL) {
        if (p->price < avg) {
            p->price *= 1.2;
        } else {
            p->price *= 1.1;
        }
        printf("%s %s %.2f\n", p->id, p->name, p->price);
        p = p->next;
    }

    // 释放链表内存
    p = head;
    while (p != NULL) {
        q = p->next;
        free(p);
        p = q;
    }

    return 0;
}