c语言 printbook（book）

在C语言中，"printbook(book)"通常表示打印书籍的功能，但这并不是一个内置函数，因为C标准库并没有提供直接用于打印书籍内容的函数。如果你想模拟这个功能，你需要创建一个自定义函数，它接收一个指向书籍结构体（如struct Book* book）的指针，并通过该指针访问书名、作者、章节等信息，然后使用printf或其他输出函数将这些信息显示出来。

例如，假设有一个简单的书籍结构体定义如下：

#include <stdio.h>

typedef struct {
    char title[50];
    char author[50];
    int chapters;
} Book;

void printBook(Book *book) {
    printf("书名: %s\n", book->title);
    printf("作者: %s\n", book->author);
    printf("章节数: %d\n", book->chapters);
}

你可以像下面这样使用这个函数：

int main() {
    Book myBook = {"计算机程序设计艺术", "Donald E. Knuth", 3};
    printBook(&myBook);
    return 0;
}

在这个例子中，`printBook`函数就是实现了打印书籍信息的功能。

相关问题

以下程序的输出结果是()。 fo = open( " book. txt" , " w") ls = [C语言', 'Java' , 'C#' , 'Python'] fo.writelines(ls) fo.close() A C语言"Java"C#'Python' B C语言， Java，C#，Python C [C语言，Java，C#，Python] D [C语言', 'Java' , 'C#' , 'Python']

选项 D：`[C语言', 'Java' , 'C#' , 'Python']`。

解析：

程序首先以写入模式打开文件 `book.txt`，然后将字符串列表 `ls` 中的元素写入文件。由于使用的是 `writelines` 方法，因此写入的每个元素不会自动添加换行符。最后关闭文件。因此，输出结果为字符串列表 `ls`。

完整的程序如下：

fo = open("book.txt", "w")
ls = ['C语言', 'Java', 'C#', 'Python']
fo.writelines(ls)
fo.close()

print(ls)
# 输出：['C语言', 'Java', 'C#', 'Python']

图书管理系统c语言

图书管理系统可以分为两个部分：前端与后端。前端即用户交互界面，后端则负责数据管理。

以下是一个简单的图书管理系统的C语言代码示例：

前端：

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

#define MAX_BOOKS 100

typedef struct Book {
    char title[100];
    char author[50];
    char publisher[50];
    int year;
} Book;

void print_menu() {
    printf("\n");
    printf("1. Add book\n");
    printf("2. Remove book\n");
    printf("3. Print books\n");
    printf("4. Exit\n");
    printf("\n");
}

void add_book(Book books[], int *num_books) {
    if (*num_books == MAX_BOOKS) {
        printf("Error: Maximum number of books reached.\n");
        return;
    }

    Book book;
    printf("Title: ");
    fgets(book.title, 100, stdin);
    book.title[strcspn(book.title, "\n")] = 0; // remove trailing newline
    printf("Author: ");
    fgets(book.author, 50, stdin);
    book.author[strcspn(book.author, "\n")] = 0; // remove trailing newline
    printf("Publisher: ");
    fgets(book.publisher, 50, stdin);
    book.publisher[strcspn(book.publisher, "\n")] = 0; // remove trailing newline
    printf("Year: ");
    scanf("%d", &book.year);
    getchar(); // remove trailing newline

    books[*num_books] = book;
    (*num_books)++;
}

void remove_book(Book books[], int *num_books) {
    if (*num_books == 0) {
        printf("Error: No books to remove.\n");
        return;
    }

    char title[100];
    printf("Title: ");
    fgets(title, 100, stdin);
    title[strcspn(title, "\n")] = 0; // remove trailing newline

    int i;
    for (i = 0; i < *num_books; i++) {
        if (strcmp(books[i].title, title) == 0) {
            break;
        }
    }

    if (i == *num_books) {
        printf("Error: Book not found.\n");
    } else {
        for (int j = i; j < *num_books - 1; j++) {
            books[j] = books[j + 1];
        }
        (*num_books)--;
    }
}

void print_books(Book books[], int num_books) {
    printf("%-50s%-20s%-20s%-10s\n", "Title", "Author", "Publisher", "Year");
    for (int i = 0; i < num_books; i++) {
        printf("%-50s%-20s%-20s%-10d\n", books[i].title, books[i].author, books[i].publisher, books[i].year);
    }
}

int main() {
    Book books[MAX_BOOKS];
    int num_books = 0;

    while (1) {
        print_menu();

        int choice;
        printf("Choice: ");
        scanf("%d", &choice);
        getchar(); // remove trailing newline

        switch (choice) {
            case 1:
                add_book(books, &num_books);
                break;
            case 2:
                remove_book(books, &num_books);
                break;
            case 3:
                print_books(books, num_books);
                break;
            case 4:
                return 0;
            default:
                printf("Error: Invalid choice.\n");
        }
    }
}

后端：

由于数据存储方式有多种，这里只提供一种简单的实现方式，即使用文件存储数据。

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

#define MAX_BOOKS 100

typedef struct Book {
    char title[100];
    char author[50];
    char publisher[50];
    int year;
} Book;

void add_book(Book book) {
    FILE *file = fopen("books.dat", "ab");

    if (file == NULL) {
        printf("Error: Could not open file.\n");
        return;
    }

    fwrite(&book, sizeof(Book), 1, file);

    fclose(file);
}

void remove_book(char *title) {
    FILE *file = fopen("books.dat", "rb");

    if (file == NULL) {
        printf("Error: Could not open file.\n");
        return;
    }

    Book book;
    int found = 0;

    FILE *temp = fopen("temp.dat", "wb");

    while (fread(&book, sizeof(Book), 1, file) == 1) {
        if (strcmp(book.title, title) != 0) {
            fwrite(&book, sizeof(Book), 1, temp);
        } else {
            found = 1;
        }
    }

    fclose(file);
    fclose(temp);

    remove("books.dat");
    rename("temp.dat", "books.dat");

    if (!found) {
        printf("Error: Book not found.\n");
    }
}

void print_books() {
    FILE *file = fopen("books.dat", "rb");

    if (file == NULL) {
        printf("Error: Could not open file.\n");
        return;
    }

    Book book;

    printf("%-50s%-20s%-20s%-10s\n", "Title", "Author", "Publisher", "Year");

    while (fread(&book, sizeof(Book), 1, file) == 1) {
        printf("%-50s%-20s%-20s%-10d\n", book.title, book.author, book.publisher, book.year);
    }

    fclose(file);
}

int main() {
    while (1) {
        printf("\n");
        printf("1. Add book\n");
        printf("2. Remove book\n");
        printf("3. Print books\n");
        printf("4. Exit\n");
        printf("\n");

        int choice;
        printf("Choice: ");
        scanf("%d", &choice);
        getchar(); // remove trailing newline

        switch (choice) {
            case 1: {
                Book book;
                printf("Title: ");
                fgets(book.title, 100, stdin);
                book.title[strcspn(book.title, "\n")] = 0; // remove trailing newline
                printf("Author: ");
                fgets(book.author, 50, stdin);
                book.author[strcspn(book.author, "\n")] = 0; // remove trailing newline
                printf("Publisher: ");
                fgets(book.publisher, 50, stdin);
                book.publisher[strcspn(book.publisher, "\n")] = 0; // remove trailing newline
                printf("Year: ");
                scanf("%d", &book.year);
                getchar(); // remove trailing newline

                add_book(book);
                break;
            }
            case 2: {
                char title[100];
                printf("Title: ");
                fgets(title, 100, stdin);
                title[strcspn(title, "\n")] = 0; // remove trailing newline

                remove_book(title);
                break;
            }
            case 3:
                print_books();
                break;
            case 4:
                return 0;
            default:
                printf("Error: Invalid choice.\n");
        }
    }
}

这只是一个简单的示例，实际上图书管理系统还有很多细节需要考虑，比如数据校验、数据查询、数据备份等等。