用c语言写，图书借阅管理系统 主要分为两⼤功能： 1)图书管理(增加图书、查询图书、删除图书、图书借阅、还书)； 2)会员管理(增加会员、查询会员、删除会员、借书信息)；

以下是用C语言实现的图书借阅管理系统代码，包括图书管理和会员管理两大功能：

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

#define MAX_BOOKS 100
#define MAX_MEMBERS 100

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

typedef struct {
    char name[50];
    char email[50];
    int books_borrowed[MAX_BOOKS];
    int num_books_borrowed;
} Member;

Book books[MAX_BOOKS];
Member members[MAX_MEMBERS];
int num_books = 0;
int num_members = 0;

void add_book() {
    if (num_books == MAX_BOOKS) {
        printf("Error: book database is full\n");
        return;
    }

    printf("Enter book title: ");
    scanf("%s", books[num_books].title);

    printf("Enter book author: ");
    scanf("%s", books[num_books].author);

    printf("Enter number of copies: ");
    scanf("%d", &books[num_books].copies);

    num_books++;

    printf("Book added successfully!\n");
}

void search_book() {
    char title[50];
    int i, found = 0;

    printf("Enter book title: ");
    scanf("%s", title);

    for (i = 0; i < num_books; i++) {
        if (strcmp(title, books[i].title) == 0) {
            printf("Title: %s\nAuthor: %s\nCopies: %d\n", books[i].title, books[i].author, books[i].copies);
            found = 1;
            break;
        }
    }

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

void delete_book() {
    char title[50];
    int i, found = 0;

    printf("Enter book title: ");
    scanf("%s", title);

    for (i = 0; i < num_books; i++) {
        if (strcmp(title, books[i].title) == 0) {
            books[i] = books[num_books - 1];
            num_books--;
            found = 1;
            break;
        }
    }

    if (found) {
        printf("Book deleted successfully!\n");
    } else {
        printf("Book not found!\n");
    }
}

void borrow_book() {
    char title[50];
    int i, j, found = 0, member_id;

    printf("Enter book title: ");
    scanf("%s", title);

    for (i = 0; i < num_books; i++) {
        if (strcmp(title, books[i].title) == 0) {
            if (books[i].copies == 0) {
                printf("All copies of this book are currently borrowed!\n");
                return;
            }

            printf("Enter member ID: ");
            scanf("%d", &member_id);

            for (j = 0; j < num_members; j++) {
                if (member_id == j) {
                    if (members[j].num_books_borrowed == MAX_BOOKS) {
                        printf("Error: member has borrowed maximum number of books!\n");
                        return;
                    }

                    members[j].books_borrowed[members[j].num_books_borrowed] = i;
                    members[j].num_books_borrowed++;

                    books[i].copies--;

                    printf("Book borrowed successfully!\n");
                    found = 1;
                    break;
                }
            }

            if (!found) {
                printf("Member not found!\n");
            }

            break;
        }
    }

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

void return_book() {
    char title[50];
    int i, j, found = 0, member_id;

    printf("Enter book title: ");
    scanf("%s", title);

    for (i = 0; i < num_books; i++) {
        if (strcmp(title, books[i].title) == 0) {
            printf("Enter member ID: ");
            scanf("%d", &member_id);

            for (j = 0; j < num_members; j++) {
                if (member_id == j) {
                    int k, found_book = 0;

                    for (k = 0; k < members[j].num_books_borrowed; k++) {
                        if (members[j].books_borrowed[k] == i) {
                            members[j].books_borrowed[k] = members[j].books_borrowed[members[j].num_books_borrowed - 1];
                            members[j].num_books_borrowed--;

                            books[i].copies++;

                            printf("Book returned successfully!\n");
                            found_book = 1;
                            break;
                        }
                    }

                    if (!found_book) {
                        printf("Error: member has not borrowed this book!\n");
                    }

                    found = 1;
                    break;
                }
            }

            if (!found) {
                printf("Member not found!\n");
            }

            break;
        }
    }

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

void add_member() {
    if (num_members == MAX_MEMBERS) {
        printf("Error: member database is full\n");
        return;
    }

    printf("Enter member name: ");
    scanf("%s", members[num_members].name);

    printf("Enter member email: ");
    scanf("%s", members[num_members].email);

    members[num_members].num_books_borrowed = 0;

    num_members++;

    printf("Member added successfully!\n");
}

void search_member() {
    char name[50];
    int i, found = 0;

    printf("Enter member name: ");
    scanf("%s", name);

    for (i = 0; i < num_members; i++) {
        if (strcmp(name, members[i].name) == 0) {
            printf("Name: %s\nEmail: %s\n", members[i].name, members[i].email);
            found = 1;
            break;
        }
    }

    if (!found) {
        printf("Member not found!\n");
    }
}

void delete_member() {
    char name[50];
    int i, found = 0;

    printf("Enter member name: ");
    scanf("%s", name);

    for (i = 0; i < num_members; i++) {
        if (strcmp(name, members[i].name) == 0) {
            members[i] = members[num_members - 1];
            num_members--;
            found = 1;
            break;
        }
    }

    if (found) {
        printf("Member deleted successfully!\n");
    } else {
        printf("Member not found!\n");
    }
}

void borrow_info() {
    int i, j;

    printf("Enter member ID: ");
    scanf("%d", &i);

    printf("Name: %s\nEmail: %s\nBooks borrowed:\n", members[i].name, members[i].email);

    for (j = 0; j < members[i].num_books_borrowed; j++) {
        printf("%s\n", books[members[i].books_borrowed[j]].title);
    }
}

int main() {
    int choice;

    while (1) {
        printf("\n1. Add book\n2. Search book\n3. Delete book\n4. Borrow book\n5. Return book\n6. Add member\n7. Search member\n8. Delete member\n9. Borrowing info\n10. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                add_book();
                break;
            case 2:
                search_book();
                break;
            case 3:
                delete_book();
                break;
            case 4:
                borrow_book();
                break;
            case 5:
                return_book();
                break;
            case 6:
                add_member();
                break;
            case 7:
                search_member();
                break;
            case 8:
                delete_member();
                break;
            case 9:
                borrow_info();
                break;
            case 10:
                exit(0);
            default:
                printf("Invalid choice!\n");
        }
    }

    return 0;
}

在上面的代码中，我们使用了两个结构体Book和Member来分别存储图书和会员的信息。在各个功能函数中，我们使用了循环和条件语句来实现对图书和会员的增删查改等操作。我们使用了scanf函数来从用户输入中读取数据，使用printf函数来向用户输出信息。最后，我们使用了一个菜单循环来实现用户与程序的交互。