写一个图书管理系统c语言

好的，下面是一个简单的图书管理系统的C语言代码示例：

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

#define MAX_BOOKS 100

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

Book bookList[MAX_BOOKS];
int numBooks = 0;

void addBook() {
    if (numBooks >= MAX_BOOKS) {
        printf("Error: book list is full\n");
        return;
    }

    Book newBook;
    printf("Enter book title: ");
    scanf(" %[^\n]s", newBook.title);
    printf("Enter book author: ");
    scanf(" %[^\n]s", newBook.author);
    printf("Enter publication year: ");
    scanf("%d", &newBook.year);
    printf("Enter number of copies: ");
    scanf("%d", &newBook.copies);

    bookList[numBooks++] = newBook;
    printf("Book added successfully!\n");
}

void displayBooks() {
    if (numBooks == 0) {
        printf("No books in library\n");
        return;
    }

    printf("%-30s %-20s %-10s %-10s\n", "Title", "Author", "Year", "Copies");
    for (int i = 0; i < numBooks; i++) {
        printf("%-30s %-20s %-10d %-10d\n", bookList[i].title, bookList[i].author, bookList[i].year, bookList[i].copies);
    }
}

void searchBooks() {
    if (numBooks == 0) {
        printf("No books in library\n");
        return;
    }

    char query[100];
    printf("Enter search query: ");
    scanf(" %[^\n]s", query);

    printf("%-30s %-20s %-10s %-10s\n", "Title", "Author", "Year", "Copies");
    for (int i = 0; i < numBooks; i++) {
        if (strstr(bookList[i].title, query) != NULL || strstr(bookList[i].author, query) != NULL) {
            printf("%-30s %-20s %-10d %-10d\n", bookList[i].title, bookList[i].author, bookList[i].year, bookList[i].copies);
        }
    }
}

void borrowBook() {
    if (numBooks == 0) {
        printf("No books in library\n");
        return;
    }

    char query[100];
    printf("Enter book title to borrow: ");
    scanf(" %[^\n]s", query);

    for (int i = 0; i < numBooks; i++) {
        if (strcmp(bookList[i].title, query) == 0) {
            if (bookList[i].copies > 0) {
                bookList[i].copies--;
                printf("Book borrowed successfully!\n");
                return;
            } else {
                printf("All copies of this book are borrowed\n");
                return;
            }
        }
    }

    printf("Book not found\n");
}

void returnBook() {
    if (numBooks == 0) {
        printf("No books in library\n");
        return;
    }

    char query[100];
    printf("Enter book title to return: ");
    scanf(" %[^\n]s", query);

    for (int i = 0; i < numBooks; i++) {
        if (strcmp(bookList[i].title, query) == 0) {
            bookList[i].copies++;
            printf("Book returned successfully!\n");
            return;
        }
    }

    printf("Book not found\n");
}

int main() {
    int choice;

    do {
        printf("\nLibrary Management System\n");
        printf("---------------------------\n");
        printf("1. Add book\n");
        printf("2. Display all books\n");
        printf("3. Search books\n");
        printf("4. Borrow book\n");
        printf("5. Return book\n");
        printf("0. Exit\n");
        printf("Enter choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                addBook();
                break;
            case 2:
                displayBooks();
                break;
            case 3:
                searchBooks();
                break;
            case 4:
                borrowBook();
                break;
            case 5:
                returnBook();
                break;
            case 0:
                printf("Exiting...\n");
                break;
            default:
                printf("Invalid choice\n");
        }
    } while (choice != 0);

    return 0;
}

这个图书管理系统可以实现添加、展示、搜索、借书和还书等基本功能。需要注意的是，这只是一个简单的示例代码，实际使用中需要根据具体需求进行修改和完善。