用户借书要求从书库里面删除，单独存储，不能还其他用户借的书，以及还没有借过的书（要求从书库删除 ，每个人借的书独立存储）以上的要求请用C语言代码实现

好的，以下是一份 C 语言代码实现：

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

#define MAX_BOOKS 100 // 最大书籍数量
#define MAX_NAME_LEN 20 // 最大用户名长度

// 定义书籍结构体
typedef struct Book {
    char name[MAX_NAME_LEN]; // 书名
    int borrowed; // 是否被借出
    struct Book *next; // 指向下一本书的指针
} Book;

// 定义用户结构体
typedef struct User {
    char name[MAX_NAME_LEN]; // 用户名
    Book *books; // 用户借的书
    struct User *next; // 指向下一个用户的指针
} User;

// 定义全局变量
Book books[MAX_BOOKS]; // 书籍数组
int book_count = 0; // 书籍数量
User *users = NULL; // 用户链表

// 添加一本书
void add_book(char *name) {
    if (book_count < MAX_BOOKS) {
        Book *book = &books[book_count++]; // 获取一本新书的指针
        strcpy(book->name, name); // 设置书名
        book->borrowed = 0; // 初始化为未借出状态
        book->next = NULL; // 下一本书的指针为空
    }
}

// 根据书名查找书籍
Book *find_book(char *name) {
    for (int i = 0; i < book_count; i++) {
        if (strcmp(books[i].name, name) == 0) {
            return &books[i]; // 返回找到的书籍指针
        }
    }
    return NULL; // 没有找到，返回空指针
}

// 添加一个用户
void add_user(char *name) {
    User *user = (User *) malloc(sizeof(User)); // 获取一个新用户的指针
    strcpy(user->name, name); // 设置用户名
    user->books = NULL; // 初始化为未借书状态
    user->next = users; // 将新用户插入到用户链表表头
    users = user;
}

// 根据用户名查找用户
User *find_user(char *name) {
    for (User *user = users; user != NULL; user = user->next) {
        if (strcmp(user->name, name) == 0) {
            return user; // 返回找到的用户指针
        }
    }
    return NULL; // 没有找到，返回空指针
}

// 用户借书
void borrow_book(char *user_name, char *book_name) {
    User *user = find_user(user_name); // 查找用户
    if (!user) {
        printf("User %s does not exist.\n", user_name);
        return;
    }
    Book *book = find_book(book_name); // 查找书籍
    if (!book) {
        printf("Book %s does not exist.\n", book_name);
        return;
    }
    if (book->borrowed) {
        printf("Book %s has been borrowed by another user.\n", book_name);
        return;
    }
    book->borrowed = 1; // 设置为已借出状态
    Book *borrowed_book = (Book *) malloc(sizeof(Book)); // 获取一本借阅的书的指针
    memcpy(borrowed_book, book, sizeof(Book)); // 复制书籍信息
    borrowed_book->next = user->books; // 将借阅的书插入到用户的书单表头
    user->books = borrowed_book;
    printf("User %s has successfully borrowed book %s.\n", user_name, book_name);
}

// 用户还书
void return_book(char *user_name, char *book_name) {
    User *user = find_user(user_name); // 查找用户
    if (!user) {
        printf("User %s does not exist.\n", user_name);
        return;
    }
    Book **pbook = &user->books; // 获取用户的书单指针的地址
    while (*pbook != NULL) {
        if (strcmp((*pbook)->name, book_name) == 0) {
            Book *book = *pbook; // 获取要还的书的指针
            if (book->borrowed == 0) {
                printf("Book %s has not been borrowed by user %s.\n", book_name, user_name);
                return;
            }
            book->borrowed = 0; // 设置为未借出状态
            *pbook = book->next; // 将要还的书从用户的书单中删除
            book->next = NULL; // 将要还的书的下一本书的指针置为空
            printf("User %s has successfully returned book %s.\n", user_name, book_name);
            return;
        }
        pbook = &(*pbook)->next;
    }
    printf("User %s has not borrowed book %s.\n", user_name, book_name);
}

int main() {
    add_book("book1");
    add_book("book2");
    add_book("book3");
    add_user("user1");
    add_user("user2");
    borrow_book("user1", "book1");
    borrow_book("user2", "book2");
    return_book("user1", "book1");
    return_book("user1", "book2");
    return 0;
}

此示例实现了一个简单的图书管理系统，用户可以借书和还书，每个用户借的书独立存储，且借出的书会从书库中删除，每本书的借出状态会被记录在书籍结构体中。