图书管理系统C语言数据结构

基于C语言数据结构的图书管理系统，可以采用动态链表来存储图书信息和用户信息。下面是一个简单的实现示例：

1. 定义图书信息结构体和用户信息结构体

// 图书信息结构体
typedef struct book {
    char name[50]; // 书名
    char author[20]; // 作者
    char publisher[30]; // 出版社
    int year; // 出版年份
    int stock; // 库存
    struct book *next; // 指向下一本书的指针
} Book;

// 用户信息结构体
typedef struct user {
    char username[20]; // 用户名
    char password[20]; // 密码
    int isAdmin; // 是否为管理员，0表示普通用户，1表示管理员
    struct user *next; // 指向下一个用户的指针
} User;

2. 加载图书信息和用户信息

// 从文件中加载图书信息
Book *loadBooks() {
    Book *head = NULL, *tail = NULL;
    FILE *fp = fopen("books.txt", "r");
    if (fp == NULL) {
        printf("Failed to open file: books.txt\n");
        return NULL;
    }
    char line[200];
    while (fgets(line, sizeof(line), fp)) {
        Book *book = (Book *)malloc(sizeof(Book));
        sscanf(line, "%s %s %s %d %d", book->name, book->author, book->publisher, &book->year, &book->stock);
        book->next = NULL;
        if (head == NULL) {
            head = book;
        } else {
            tail->next = book;
        }
        tail = book;
    }
    fclose(fp);
    return head;
}

// 从文件中加载用户信息
User *loadUsers() {
    User *head = NULL, *tail = NULL;
    FILE *fp = fopen("users.txt", "r");
    if (fp == NULL) {
        printf("Failed to open file: users.txt\n");
        return NULL;
    }
    char line[200];
    while (fgets(line, sizeof(line), fp)) {
        User *user = (User *)malloc(sizeof(User));
        sscanf(line, "%s %s %d", user->username, user->password, &user->isAdmin);
        user->next = NULL;
        if (head == NULL) {
            head = user;
        } else {
            tail->next = user;
        }
        tail = user;
    }
    fclose(fp);
    return head;
}

3. 登录功能

// 登录
User *login(User *users) {
    char username[20], password[20];
    printf("Please enter your username: ");
    scanf("%s", username);
    printf("Please enter your password: ");
    scanf("%s", password);
    User *user = users;
    while (user != NULL) {
        if (strcmp(user->username, username) == 0 && strcmp(user->password, password) == 0) {
            printf("Welcome, %s!\n", username);
            return user;
        }
        user = user->next;
    }
    printf("Invalid username or password.\n");
    return NULL;
}

4. 管理员功能

// 添加图书
void addBook(Book **books) {
    Book *book = (Book *)malloc(sizeof(Book));
    printf("Please enter the book name: ");
    scanf("%s", book->name);
    printf("Please enter the author: ");
    scanf("%s", book->author);
    printf("Please enter the publisher: ");
    scanf("%s", book->publisher);
    printf("Please enter the year of publication: ");
    scanf("%d", &book->year);
    printf("Please enter the stock: ");
    scanf("%d", &book->stock);
    book->next = NULL;
    if (*books == NULL) {
        *books = book;
    } else {
        Book *tail = *books;
        while (tail->next != NULL) {
            tail = tail->next;
        }
        tail->next = book;
    }
    printf("Book added successfully.\n");
}

// 删除图书
void removeBook(Book **books) {
    char name[50];
    printf("Please enter the name of the book you want to remove: ");
    scanf("%s", name);
    Book *prev = NULL, *curr = *books;
    while (curr != NULL) {
        if (strcmp(curr->name, name) == 0) {
            if (prev == NULL) {
                *books = curr->next;
            } else {
                prev->next = curr->next;
            }
            free(curr);
            printf("Book removed successfully.\n");
            return;
        }
        prev = curr;
        curr = curr->next;
    }
    printf("Book not found.\n");
}

// 修改图书信息
void modifyBook(Book *books) {
    char name[50];
    printf("Please enter the name of the book you want to modify: ");
    scanf("%s", name);
    Book *book = books;
    while (book != NULL) {
        if (strcmp(book->name, name) == 0) {
            printf("Please enter the new author: ");
            scanf("%s", book->author);
            printf("Please enter the new publisher: ");
            scanf("%s", book->publisher);
            printf("Please enter the new year of publication: ");
            scanf("%d", &book->year);
            printf("Please enter the new stock: ");
            scanf("%d", &book->stock);
            printf("Book modified successfully.\n");
            return;
        }
        book = book->next;
    }
    printf("Book not found.\n");
}

5. 普通用户功能

// 查询图书
void searchBook(Book *books) {
    char name[50];
    printf("Please enter the name of the book you want to search: ");
    scanf("%s", name);
    Book *book = books;
    while (book != NULL) {
        if (strcmp(book->name, name) == 0) {
            printf("Name: %s\n", book->name);
            printf("Author: %s\n", book->author);
            printf("Publisher: %s\n", book->publisher);
            printf("Year of publication: %d\n", book->year);
            printf("Stock: %d\n", book->stock);
            return;
        }
        book = book->next;
    }
    printf("Book not found.\n");
}

6. 主函数

int main() {
    Book *books = loadBooks();
    User *users = loadUsers();
    printf("Welcome to the library!\n");
    printf("  __  __       _ _   _      _   \n");
    printf(" |  \\/  | __ _(_) |_| | ___| |_ \n");
    printf(" | |\\/| |/ _` | | __| |/ _ \\ __|\n");
    printf(" | |  | | (_| | | |_| |  __/ |_ \n");
    printf(" |_|  |_|\\__,_|_|\\__|_|\\___|\\__|\n");
    printf("\n");
    User *user = login(users);
    while (user == NULL) {
        user = login(users);
    }
    if (user->isAdmin) {
        printf("Welcome, admin!\n");
        int choice;
        do {
            printf("Please select an option:\n");
            printf("1. Add book\n");
            printf("2. Remove book\n");
            printf("3. Modify book information\n");
            printf("4. Exit\n");
            scanf("%d", &choice);
            switch (choice) {
                case 1:
                    addBook(&books);
                    break;
                case 2:
                    removeBook(&books);
                    break;
                case 3:
                    modifyBook(books);
                    break;
                case 4:
                    break;
                default:
                    printf("Invalid choice.\n");
                    break;
            }
        } while (choice != 4);
    } else {
        printf("Welcome, user!\n");
        int choice;
        do {
            printf("Please select an option:\n");
            printf("1. Search book\n");
            printf("2. Exit\n");
            scanf("%d", &choice);
            switch (choice) {
                case 1:
                    searchBook(books);
                    break;
                case 2:
                    break;
                default:
                    printf("Invalid choice.\n");
                    break;
            }
        } while (choice != 2);
    }
    return 0;
}