图书馆管理系统C语言（用数组、循环、选择、字符串结构、结构体实现）

好的，下面是用C语言数组、循环、选择、字符串结构、结构体实现的图书馆管理系统。

首先，我们需要定义图书和读者的结构体，其数据成员可以根据实际需要进行定义，例如：

struct Book {
    char title[50];     //书名
    char author[20];    //作者
    char publisher[20]; //出版社
    int ISBN;           //书籍编号
    int quantity;       //书籍数量
    int borrowed;       //已借出的数量
};

struct Reader {
    char name[20];      //读者姓名
    int ID;             //读者ID号
    int borrowed;       //已借阅的数量
    int limit;          //最大借阅数量
};

然后，我们需要定义一些基本操作，如添加图书、添加读者、查找图书、查找读者、借阅图书和归还图书等操作。这些操作可以通过循环、选择结构和字符串操作来实现。

例如，添加图书的函数可以这样实现：

void add_book(struct Book books[], int *count) {
    if (*count >= MAX_BOOKS) {
        printf("The library is full.\n");
        return;
    }
    printf("Please enter the title of the book: ");
    scanf("%s", books[*count].title);
    printf("Please enter the author of the book: ");
    scanf("%s", books[*count].author);
    printf("Please enter the publisher of the book: ");
    scanf("%s", books[*count].publisher);
    printf("Please enter the ISBN of the book: ");
    scanf("%d", &books[*count].ISBN);
    printf("Please enter the quantity of the book: ");
    scanf("%d", &books[*count].quantity);
    books[*count].borrowed = 0;
    (*count)++;
    printf("Successfully added the book.\n");
}

类似地，添加读者的函数可以这样实现：

void add_reader(struct Reader readers[], int *count) {
    if (*count >= MAX_READERS) {
        printf("The library is full.\n");
        return;
    }
    printf("Please enter the name of the reader: ");
    scanf("%s", readers[*count].name);
    printf("Please enter the ID of the reader: ");
    scanf("%d", &readers[*count].ID);
    printf("Please enter the limit of the reader: ");
    scanf("%d", &readers[*count].limit);
    readers[*count].borrowed = 0;
    (*count)++;
    printf("Successfully added the reader.\n");
}

查询图书的函数可以这样实现：

void search_book(struct Book books[], int count) {
    int ISBN;
    printf("Please enter the ISBN of the book: ");
    scanf("%d", &ISBN);
    for (int i = 0; i < count; i++) {
        if (books[i].ISBN == ISBN) {
            printf("Title: %s\n", books[i].title);
            printf("Author: %s\n", books[i].author);
            printf("Publisher: %s\n", books[i].publisher);
            printf("Quantity: %d\n", books[i].quantity);
            printf("Borrowed: %d\n", books[i].borrowed);
            return;
        }
    }
    printf("The book is not found.\n");
}

查询读者的函数可以这样实现：

void search_reader(struct Reader readers[], int count) {
    int ID;
    printf("Please enter the ID of the reader: ");
    scanf("%d", &ID);
    for (int i = 0; i < count; i++) {
        if (readers[i].ID == ID) {
            printf("Name: %s\n", readers[i].name);
            printf("Limit: %d\n", readers[i].limit);
            printf("Borrowed: %d\n", readers[i].borrowed);
            return;
        }
    }
    printf("The reader is not found.\n");
}

借阅图书的函数可以这样实现：

void borrow_book(struct Book books[], int book_count, struct Reader readers[], int reader_count) {
    int ISBN, ID;
    printf("Please enter the ISBN of the book: ");
    scanf("%d", &ISBN);
    printf("Please enter the ID of the reader: ");
    scanf("%d", &ID);
    int book_index = -1;
    int reader_index = -1;
    for (int i = 0; i < book_count; i++) {
        if (books[i].ISBN == ISBN) {
            book_index = i;
            break;
        }
    }
    for (int i = 0; i < reader_count; i++) {
        if (readers[i].ID == ID) {
            reader_index = i;
            break;
        }
    }
    if (book_index == -1) {
        printf("The book is not found.\n");
        return;
    }
    if (reader_index == -1) {
        printf("The reader is not found.\n");
        return;
    }
    if (books[book_index].borrowed >= books[book_index].quantity) {
        printf("The book is out of stock.\n");
        return;
    }
    if (readers[reader_index].borrowed >= readers[reader_index].limit) {
        printf("The reader has reached the maximum borrowing limit.\n");
        return;
    }
    books[book_index].borrowed++;
    readers[reader_index].borrowed++;
    printf("Successfully borrowed the book.\n");
}

归还图书的函数可以这样实现：

void return_book(struct Book books[], int book_count, struct Reader readers[], int reader_count) {
    int ISBN, ID;
    printf("Please enter the ISBN of the book: ");
    scanf("%d", &ISBN);
    printf("Please enter the ID of the reader: ");
    scanf("%d", &ID);
    int book_index = -1;
    int reader_index = -1;
    for (int i = 0; i < book_count; i++) {
        if (books[i].ISBN == ISBN) {
            book_index = i;
            break;
        }
    }
    for (int i = 0; i < reader_count; i++) {
        if (readers[i].ID == ID) {
            reader_index = i;
            break;
        }
    }
    if (book_index == -1) {
        printf("The book is not found.\n");
        return;
    }
    if (reader_index == -1) {
        printf("The reader is not found.\n");
        return;
    }
    if (books[book_index].borrowed <= 0) {
        printf("The book has not been borrowed.\n");
        return;
    }
    if (readers[reader_index].borrowed <= 0) {
        printf("The reader has not borrowed any book.\n");
        return;
    }
    books[book_index].borrowed--;
    readers[reader_index].borrowed--;
    printf("Successfully returned the book.\n");
}

最后，我们还需要一个主函数来调用这些操作函数，例如：

int main() {
    struct Book books[MAX_BOOKS];
    struct Reader readers[MAX_READERS];
    int book_count = 0;
    int reader_count = 0;
    int choice;
    do {
        printf("1. Add a book.\n");
        printf("2. Add a reader.\n");
        printf("3. Search for a book.\n");
        printf("4. Search for a reader.\n");
        printf("5. Borrow a book.\n");
        printf("6. Return a book.\n");
        printf("7. Exit.\n");
        printf("Please enter your choice: ");
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                add_book(books, &book_count);
                break;
            case 2:
                add_reader(readers, &reader_count);
                break;
            case 3:
                search_book(books, book_count);
                break;
            case 4:
                search_reader(readers, reader_count);
                break;
            case 5:
                borrow_book(books, book_count, readers, reader_count);
                break;
            case 6:
                return_book(books, book_count, readers, reader_count);
                break;
            case 7:
                break;
            default:
                printf("Invalid choice.\n");
                break;
        }
    } while (choice != 7);
    return 0;
}

以上就是用C语言数组、循环、选择、字符串结构、结构体实现的图书馆管理系统。