图书管理借阅系统（豪华版）

1：用户登录系统

• 用户角色区分（管理员/普通用户）

• 注册登录流程

• 基于角色的访问控制

• 用户数据加密存储（示例未加密，实际应加密）

• 2：借阅管理系统

• 完整的借阅/归还流程

• 借阅记录管理

• 库存自动更新

• 借阅期限管理

• 借阅记录查询

• 3：数据统计功能

• 图书总量统计

• 库存总量统计

• 最受欢迎图书分析

• 借阅趋势分析（需扩展时间处理）

• 用户借阅排行（需扩展用户系统）

3：使用说明：

• 首次使用需注册管理员账号（直接修改数据文件添加admin角色用户）

• 普通用户可进行图书查询和借阅操作

• 管理员具有完整系统管理权限

• 所有数据自动保存，记录包括：

• books.txt（图书数据）

• users.txt（用户数据）

• records.txt（借阅记录）

4：扩展建议：

• 增加密码加密存储（使用加密算法）

• 完善日期处理（使用标准日期库）

• 添加借阅逾期罚款功能

• 实现图形界面（建议使用Qt框架）

• 增加图书分类和高级搜索功能

• 完善异常处理和数据验证

5：注意事项：

• 保持数据文件格式一致性

• 重要操作需要添加确认提示

• 敏感操作需要记录操作日志

• 定期进行数据备份

• 加强输入验证防止注入攻击

#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<fstream>
#include<vector>
#include<string>
#include<map>
#include<algorithm>
#include<limits>

using namespace std;
struct Book {
	string name;
	string author;
	string isbn;
	double price;
	int quantity;
};

struct User {
	string username;
	string password;
	string role;  //admin/user
};

struct BorrowRecord {
	string username;
	string isbn;
	string borrowDate;
	string dueDate;
	bool returned;
};

vector<Book>books;
vector<User>users;
vector<BorrowRecord>borrowRecords;
User currentUser;
const string BOOK_FILE = "books.txt";
const string USER_FILE = "users.txt";
const string RECORD_FILE = "records.txt";

//文件操作函数
void loadBooks() {
	//加载图书
	ifstream bfile(BOOK_FILE);
	if (bfile.is_open()) {
		Book book;
		while (bfile >> ws && getline(bfile, book.name) && getline(bfile, book.author) && getline(bfile, book.isbn) && bfile >> book.price >> book.quantity) {
			books.push_back(book);
			bfile.ignore();
		}
		bfile.close();
	}

	//加载用户
	ifstream ufile(USER_FILE);
	User u;
	while (ufile >> ws && getline(ufile, u.username) && getline(ufile, u.password) && getline(ufile, u.role)) {
		users.push_back(u);
	}

	//加载借阅记录
	ifstream rfile(RECORD_FILE);
	BorrowRecord r;
	string returned;
	while (rfile >> ws && getline(rfile, r.username) && getline(rfile, r.isbn) && getline(rfile, r.borrowDate) && getline(rfile, r.dueDate) && getline(rfile, returned)) {
		r.returned = (returned == "1");
		borrowRecords.push_back(r);
	}
}

void saveData() {
	//保存图书
	ofstream bfile(BOOK_FILE);
	if (bfile.is_open()) {
		for (const auto& book : books) {
			bfile << book.name << "\n"
				<< book.author << "\n"
				<< book.isbn << "\n"
				<< book.price << " " << book.quantity << "\n";
		}
		bfile.close();
	}

	//保存用户
	ofstream ufile(USER_FILE);
	if (ufile.is_open()) {
		for (const auto& u : users) {
			ufile << u.username << "\n" << u.password << "\n" << u.role << "\n";
		}
	}

	//保存借阅记录
	ofstream rfile(RECORD_FILE);
	if (rfile.is_open()) {
		for (const auto& r : borrowRecords) {
			rfile << r.username << "\n" << r.isbn << "\n" << r.borrowDate << "\n" << r.dueDate << "\n" << (r.returned ? 1 : 0) << "\n";
		}
	}
}

//用户系统
void registerUser() {
	User newUser;
	cout << "请输入用户名" << endl;
	getline(cin, newUser.username);
	if (any_of(users.begin(), users.end(), [&](const User& u) {return u.username == newUser.username; })) {
		cout << "用户名已经存在！" << endl;
		return;
	}
	cout << "请输入密码" << endl;
	getline(cin, newUser.password);
	newUser.role = "user";
	users.push_back(newUser);
	saveData();
	cout << "注册成功" << endl;

}

void login() {
	string username, password;
	cout << "用户名：";
	getline(cin, username);
	cout << "密码：";
	getline(cin, password);
	auto it = find_if(users.begin(), users.end(), [&](const User& u) {return u.username == username && u.password == password; });
	if (it != users.end()) {
		currentUser = *it;
		cout << "登录成功！ 欢迎" <<currentUser.username<< endl;
	}
	else {
		cout << "用户名或密码错误！\n";
	}
}

//借阅管理
string getCurrentDate() {
	time_t now = time(0);
	tm* ltm = localtime(&now);
	return to_string(1900 + ltm->tm_year) + "-" + to_string(1 + ltm->tm_mon) + "-" + to_string(ltm->tm_mday);
}

void borrowBook() {
	string isbn;
	cout << "请输入要借阅图书的ISBN：";
	getline(cin, isbn);
	auto bookIt = find_if(books.begin(), books.end(), [&](const Book& b) {return b.isbn == isbn; });
	if (bookIt == books.end()) {
		cout << "图书不存在" << endl;
		return;
	}
	if (bookIt->quantity <= 0) {
		cout << "该书已无库存！" << endl;
		return;
	}
	BorrowRecord record;
	record.username = currentUser.username;
	record.isbn = isbn;
	record.borrowDate = getCurrentDate();
	record.dueDate = "2024-12-31";
	record.returned = false;

	borrowRecords.push_back(record);
	bookIt->quantity--;
	saveData();
	cout << "借阅成功！" << endl;
}

void returnBook() {
	string isbn;
	cout << "输入归还图书的ISBN：";
	getline(cin, isbn);
	auto recordIt = find_if(borrowRecords.begin(), borrowRecords.end(), [&](const BorrowRecord& r) {return r.isbn == isbn&&currentUser.username==r.username&&!r.returned; });
	if (recordIt == borrowRecords.end()) {
		cout << "未找到借阅记录！" << endl;
	}
	else {
		recordIt->returned = true;
		auto bookIt = find_if(books.begin(), books.end(), [&](const Book& b) {return b.isbn == isbn; });
		if (bookIt != books.end()) {
			bookIt->quantity++;
			saveData();
			cout << "归还成功！" << endl;
		}
	}
}

void showMyBorrowRecord() {
	for (const auto& x : borrowRecords) {
		if (x.username == currentUser.username) {
			cout << "图书的ISBN: " << x.isbn
				<< "图书的借阅时间：" << x.borrowDate
				<< "图书的归还时间：" << x.dueDate
				<< "图书是否归还：" << x.returned;
		}
		cout << "==============";
	}
}

//数据统计
void showStatistics() {
	cout << "\n===== 数据统计 =====\n";
	cout << "1. 图书总数：" << books.size() << endl;
	int totalQuantity = 0;
	for (const auto& b : books) {
		totalQuantity += b.quantity;
	}
	cout << "2. 总库存：" << totalQuantity << endl;

	//最受欢迎图书统计
	map<string, int>borrowCount;
	for (const auto& r : borrowRecords) {
		borrowCount[r.isbn]++;
	}
	if (!borrowCount.empty()) {
		auto maxIt = max_element(borrowCount.begin(), borrowCount.end(), [](const pair<string, int>& a, const pair<string, int>& b){ return a.second < b.second; });
		auto bookIt = find_if(books.begin(), books.end(), [&](const Book& b) {return b.isbn == maxIt->first; });
		cout << "3. 最受欢迎的图书：\n"
			<< "  书名：" << bookIt->name << "\n"
			<< "  借阅次数：" << maxIt->second << endl;
	}
}

//菜单系统
void userMenu() {
	cout << "\n===== 用户菜单 =====\n"
		<< "1. 查询图书\n"
		<<"2. 借阅图书\n"
		<<"3. 归还图书\n"
		<<"4. 查看我的借阅记录\n"
		<< "5. 退出登录\n";
}

void adminMenu() {
	cout<<"\n===== 管理员菜单 =====\n"
		<<"1. 添加图书\n"
		<<"2. 删除图书\n"
		<<"3. 修改图书\n"
		<<"4. 显示所有图书\n"
		<<"5. 数据统计\n"
		<< "6. 退出系统\n";
}
//核心功能函数
void addBook() {
	Book newbook;
	cout << "输入书名：";
	getline(cin, newbook.name);
	cout << "输入作者：";
	getline(cin, newbook.author);
	cout << "输入ISBN：";
	getline(cin, newbook.isbn);
	// 检查ISBN是否已存在
	if (any_of(books.begin(), books.end(), [&](const Book& b) {
		return b.isbn == newbook.isbn;
		})) {
		cout << "错误：ISBN已存在！\n";
		return;
	}
	cout << "输入价格：";
	cin >> newbook.price;
	cout << "输入库存量：";
	cin >> newbook.quantity;
	cin.ignore();
}

void deleteBook() {
	string isbn;
	cout << "输入要删除的图书ISBN：";
	getline(cin, isbn);
	auto it = find_if(books.begin(), books.end(), [&](const Book& b) {return b.isbn == isbn; });
	if (it != books.end()) {
		books.erase(it);
		cout << "图书删除成功！\n";
	}
	else {
		cout << "未找到对应ISBN的图书！\n";
	}
}

void searchBook() {
	string keyword;
	cout << "输入搜索关键词（书名/作者/ISBN）：";
	getline(cin, keyword);
	vector<Book>results;
	for (const Book& book : books) {
		if (book.name.find(keyword) != string::npos || book.author.find(keyword) != string::npos || book.isbn.find(keyword) != string::npos)
		{
			results.push_back(book);
		}
	}
	if (results.empty()) {
		cout << "未找到相关图书！\n";
		return;
	}
	cout << "\n搜索结果：\n";
	for (const auto& book : results) {
		cout << "书名：" << book.name << "\n"
			<< "作者：" << book.author << "\n"
			<< "ISBN：" << book.isbn << "\n"
			<< "价格：" << book.price << "\n"
			<< "库存：" << book.quantity << "\n\n";
	}
}

void modifyBook() {
	string isbn;
	cout << "输入要修改的图书ISBN：";
	getline(cin, isbn);
	auto it = find_if(books.begin(), books.end(), [&](Book& b) {return b.isbn == isbn; });
	if (it == books.end()) {
		cout << "未找到对应ISBN的图书！\n";
		return;
	}
	Book& book = *it;
	cout << "当前信息：\n"
		<< "书名：" << book.name << "\n"
		<< "作者：" << book.author << "\n"
		<< "价格：" << book.price << "\n"
		<< "库存：" << book.quantity << "\n";
	cout << "输入新书名（留空保持不变）：";
	string input;
	getline(cin, input);
	if (!input.empty()) book.name = input;
	cout << "输入新作者（留空保持不变）：";
	getline(cin, input);
	if (!input.empty()) book.author = input;
	cout << "输入新价格（输入0保持不变）：";
	double newPrice;
	cin >> newPrice;
	if (newPrice > 0) book.price = newPrice;
	cout << "输入新库存（输入-1保持不变）：";
	int newQty;
	cin >> newQty;
	if (newQty >= 0) book.quantity = newQty;
	cin.ignore();
	cout << "修改成功！\n";
}

void displayAll() {
	if (books.empty()) {
		cout << "当前没有图书记录！\n";
		return;
	}
	cout << "\n所有图书信息：\n";
	for (const auto& book : books) {
		cout << "---------------\n"
			<< "书名：" << book.name << "\n"
			<< "作者：" << book.author << "\n"
			<< "ISBN：" << book.isbn << "\n"
			<< "价格：" << book.price << "\n"
			<< "库存：" << book.quantity << "\n";
	}
	cout << "---------------\n";
}

int main() {
	loadBooks();
	while (true) {
		if (currentUser.username.empty()) {
			cout<<"\n===== 主界面 =====\n"
				<<"1. 登录\n"
				<<"2. 注册\n"
				<<"3. 退出\n"
				<< "请选择：";
			int choice;
			cin >> choice;
			cin.ignore();
			switch (choice) {
			case 1:login(); break;
			case 2:registerUser(); break;
			case 3:saveData(); exit(0);
			default:cout << "无效选择！" << endl;
			}
		}
		else {
			while (true) {
				if (currentUser.role == "admin") {
					adminMenu();
					int choice;
					cin >> choice;
					cin.ignore();
					switch (choice) {
					case 1:addBook(); break;
					case 2:deleteBook(); break;
					case 3:modifyBook(); break;
					case 4:displayAll(); break;
					case 5:showStatistics(); break;
					case 6:saveData(); cout << "谢谢使用!\n"; return 0;
					default:cout << "无效输入，请重新输入！\n";
					}

				}
				else {
					userMenu();
					int choice;
					cin >> choice;
					switch (choice) {
					case 1:searchBook(); break;
					case 2:borrowBook(); break;
					case 3:returnBook; break;
					case 4:showMyBorrowRecord(); break;
					case 5:saveData(); cout << "谢谢使用!\n"; return 0;
					default:cout << "无效输入，请重新输入！\n";
					}
				}
			}
		}
	}


	return 0;
}