帮我用c语言写一个图书管理系统

好的，以下是一个简单的图书管理系统的代码示例：

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

#define MAX_BOOKS 100

struct Book {
    char title[50];
    char author[50];
    int id;
    int availability;
};

struct Library {
    struct Book books[MAX_BOOKS];
    int num_books;
};

void add_book(struct Library* library);
void remove_book(struct Library* library, int book_id);
void display_books(struct Library* library);
void borrow_book(struct Library* library, int book_id);
void return_book(struct Library* library, int book_id);

int main() {
    struct Library library;
    library.num_books = 0;

    int choice = 0;
    do {
        printf("\n1. Add book\n");
        printf("2. Remove book\n");
        printf("3. Display books\n");
        printf("4. Borrow book\n");
        printf("5. Return book\n");
        printf("6. Exit\n");
        printf("Enter choice: ");
        scanf("%d", &choice);

        switch(choice) {
            case 1:
                add_book(&library);
                break;
            case 2:
                printf("Enter book ID to remove: ");
                int book_id;
                scanf("%d", &book_id);
                remove_book(&library, book_id);
                break;
            case 3:
                display_books(&library);
                break;
            case 4:
                printf("Enter book ID to borrow: ");
                scanf("%d", &book_id);
                borrow_book(&library, book_id);
                break;
            case 5:
                printf("Enter book ID to return: ");
                scanf("%d", &book_id);
                return_book(&library, book_id);
                break;
            case 6:
                printf("Exiting program...\n");
                break;
            default:
                printf("Invalid choice. Please try again.\n");
                break;
        }
    } while (choice != 6);

    return 0;
}

void add_book(struct Library* library) {
    if (library->num_books >= MAX_BOOKS) {
        printf("Library is full. Cannot add more books.\n");
        return;
    }

    struct Book book;
    printf("\nEnter book title: ");
    scanf("%s", book.title);
    printf("Enter author name: ");
    scanf("%s", book.author);
    printf("Enter book ID: ");
    scanf("%d", &book.id);
    book.availability = 1;

    library->books[library->num_books] = book;
    library->num_books++;
    printf("Book added successfully.\n");
}

void remove_book(struct Library* library, int book_id) {
    int i;
    for (i = 0; i < library->num_books; i++) {
        if (library->books[i].id == book_id) {
            // Shift all the books after i one position to the left
            int j;
            for (j = i; j < library->num_books - 1; j++) {
                library->books[j] = library->books[j + 1];
            }
            library->num_books--;
            printf("Book removed successfully.\n");
            return;
        }
    }
    printf("Book not found.\n");
}

void display_books(struct Library* library) {
    if (library->num_books == 0) {
        printf("Library is empty.\n");
        return;
    }

    printf("\nBooks in library:\n");
    printf("ID\tTitle\t\tAuthor\t\tAvailability\n");
    int i;
    for (i = 0; i < library->num_books; i++) {
        printf("%d\t%s\t%s\t%s\n", library->books[i].id, library->books[i].title,
               library->books[i].author, library->books[i].availability == 1 ? "Available" : "Not available");
    }
}

void borrow_book(struct Library* library, int book_id) {
    int i;
    for (i = 0; i < library->num_books; i++) {
        if (library->books[i].id == book_id) {
            if (library->books[i].availability == 1) {
                library->books[i].availability = 0;
                printf("Book borrowed successfully.\n");
                return;
            } else {
                printf("Book is not available for borrowing.\n");
                return;
            }
        }
    }
    printf("Book not found.\n");
}

void return_book(struct Library* library, int book_id) {
    int i;
    for (i = 0; i < library->num_books; i++) {
        if (library->books[i].id == book_id) {
            if (library->books[i].availability == 0) {
                library->books[i].availability = 1;
                printf("Book returned successfully.\n");
                return;
            } else {
                printf("Book was not borrowed.\n");
                return;
            }
        }
    }
    printf("Book not found.\n");
}

这个程序使用了结构体来表示图书和图书馆。具体来说，每本书都有一个标题、作者、ID 和可用性状态（1 表示可借，0 表示不可借），而图书馆则包含一个 Book 数组以及记录图书数量的 num_books 变量。程序中提供了以下功能：

- 添加图书（add_book）
- 移除图书（remove_book）
- 显示图书馆中的所有图书（display_books）
- 借阅图书（borrow_book）
- 归还图书（return_book）

你可以根据实际需求修改这些功能，也可以添加其他功能，例如搜索图书、排序图书等等。