创建链表并读入图书信息。 计算所有图书的平均价格，并调整价格。 查找价格最高的图书。 插入新图书到指定位置。 删除指定位置的旧图书。使用c语言写代码

在C语言中，我们可以创建一个简单的链表结构来存储图书信息。这里是一个基本的例子，包括链表操作：

首先，我们需要定义一个结构体来表示一本书，包含书名、作者和价格：

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

typedef struct Book {
    char title[50];
    char author[50];
    float price;
    struct Book* next; // 指向下一个节点
} Book;

接下来，我们实现链表的基本操作：

1. **创建链表**:

Book* createList() {
    Book* head = NULL;
    return head;
}

void insert(Book** head, char* title, char* author, float price) {
    Book* newNode = (Book*)malloc(sizeof(Book));
    newNode->title = strcpy(newNode->title, title);
    newNode->author = strcpy(newNode->author, author);
    newNode->price = price;
    newNode->next = *head;
    *head = newNode;
}

2. **读入图书信息**:
由于这是在内存中操作，实际读取需要从用户输入或其他数据源获取，这里简化为直接赋值：

void input(Book** head) {
    // 这里仅做假设，实际应有输入处理
    char title[50], author[50];
    float price;
    scanf("Title: %s Author: %s Price: %f", title, author, &price);
    insert(head, title, author, price);
}

3. **计算平均价格**:

float averagePrice(Book* head) {
    if (head == NULL) return 0.0;
    float sum = 0.0, count = 1.0;
    Book* temp = head;
    while (temp != NULL) {
        sum += temp->price;
        count++;
        temp = temp->next;
    }
    return sum / count;
}

4. **查找价格最高图书**:

Book* findHighestPrice(Book* head) {
    if (head == NULL) return NULL;
    Book* maxPriceNode = head;
    Book* temp = head->next;
    while (temp != NULL) {
        if (temp->price > maxPriceNode->price) {
            maxPriceNode = temp;
        }
        temp = temp->next;
    }
    return maxPriceNode;
}

5. **插入新图书**:

void insertAtPosition(Book** head, int position, char* title, char* author, float price) {
    if (position <= 0) {
        insert(head, title, author, price);
    } else {
        Book* newNode = (Book*)malloc(sizeof(Book));
        newNode->title = strcpy(newNode->title, title);
        newNode->author = strcpy(newNode->author, author);
        newNode->price = price;
        Book* prev = *head;
        for (int i = 1; i < position - 1 && prev != NULL; ++i) {
            prev = prev->next;
        }
        if (prev == NULL) {
            printf("Invalid position!\n");
            return;
        }
        newNode->next = prev->next;
        prev->next = newNode;
    }
}

6. **删除指定位置的图书**:

void deleteAtPosition(Book** head, int position) {
    if (position <= 0 || *head == NULL) {
        printf("Invalid position!\n");
        return;
    }

    if (position == 1) {
        Book* temp = *head;
        *head = (*head)->next;
        free(temp);
        return;
    }

    Book* curr = *head;
    for (int i = 1; i < position - 1 && curr != NULL; ++i) {
        curr = curr->next;
    }
    if (curr == NULL) {
        printf("Invalid position!\n");
        return;
    }

    Book* nextNode = curr->next;
    curr->next = nextNode->next;
    free(nextNode);
}

记得在程序结束时释放所有的链表节点：

void cleanup(Book* head) {
    Book* temp = head;
    while (temp != NULL) {
        Book* nextTemp = temp->next;
        free(temp);
        temp = nextTemp;
    }
}