i have added 'Improve scalability for large user base' feature in it

notification-docs/file.cpp

@@ -0,0 +1,108 @@
+#include <iostream>
+#include <unordered_map>
+#include <vector>
+#include <string>
+using namespace std;
+
+class Book {
+public:
+    int bookId;
+    string title;
+    string author;
+    bool isAvailable;
+
+    Book(int id, string t, string a) : bookId(id), title(t), author(a), isAvailable(true) {}
+};
+
+class User {
+public:
+    int userId;
+    string name;
+    vector<int> borrowedBooks;
+
+    User(int id, string n) : userId(id), name(n) {}
+
+    void borrowBook(int bookId) {
+        borrowedBooks.push_back(bookId);
+    }
+
+    void returnBook(int bookId) {
+        for (auto it = borrowedBooks.begin(); it != borrowedBooks.end(); ++it) {
+            if (*it == bookId) {
+                borrowedBooks.erase(it);
+                break;
+            }
+        }
+    }
+};
+
+class Library {
+private:
+    unordered_map<int, Book> books;   // Book ID as key
+    unordered_map<int, User> users;   // User ID as key
+
+public:
+    void addBook(int id, string title, string author) {
+        books[id] = Book(id, title, author);
+    }
+
+    void addUser(int id, string name) {
+        users[id] = User(id, name);
+    }
+
+    void borrowBook(int userId, int bookId) {
+        if (books[bookId].isAvailable) {
+            books[bookId].isAvailable = false;
+            users[userId].borrowBook(bookId);
+            cout << "User " << userId << " borrowed book " << bookId << endl;
+        } else {
+            cout << "Book " << bookId << " is not available" << endl;
+        }
+    }
+
+    void returnBook(int userId, int bookId) {
+        books[bookId].isAvailable = true;
+        users[userId].returnBook(bookId);
+        cout << "User " << userId << " returned book " << bookId << endl;
+    }
+
+    void searchBook(int bookId) {
+        if (books.find(bookId) != books.end()) {
+            Book book = books[bookId];
+            cout << "Book ID: " << book.bookId << ", Title: " << book.title << ", Author: " << book.author << ", Available: " << (book.isAvailable ? "Yes" : "No") << endl;
+        } else {
+            cout << "Book not found!" << endl;
+        }
+    }
+
+    void displayAllBooks() {
+        for (auto &b : books) {
+            cout << "Book ID: " << b.second.bookId << ", Title: " << b.second.title << ", Author: " << b.second.author << ", Available: " << (b.second.isAvailable ? "Yes" : "No") << endl;
+        }
+    }
+};
+
+int main() {
+    Library lib;
+
+    // Adding books
+    lib.addBook(1, "The Catcher in the Rye", "J.D. Salinger");
+    lib.addBook(2, "To Kill a Mockingbird", "Harper Lee");
+    lib.addBook(3, "1984", "George Orwell");
+
+    // Adding users
+    lib.addUser(101, "Alice");
+    lib.addUser(102, "Bob");
+
+    // Borrow and return operations
+    lib.borrowBook(101, 1);  // Alice borrows "The Catcher in the Rye"
+    lib.borrowBook(102, 2);  // Bob borrows "To Kill a Mockingbird"
+    lib.returnBook(101, 1);  // Alice returns the book
+    lib.borrowBook(101, 3);  // Alice borrows "1984"
+
+    // Search and display operations
+    lib.searchBook(1);  // Search for book with ID 1
+    lib.displayAllBooks();  // Display all books
+
+    return 0;
+}