综合-图书管理系统

def solve():
    class Book:
        def __init__(____):
            self.title = title
            self.author = author
            self.available = True
    class Library:
        def __init__(____):
            self.books = {}
        def add_book(____):
            self.books[book.title] = book
        def borrow_book(____):
            if title in self.books and self.books[title].available:
                self.books[title].available = False
                return True
            return False
        def return_book(____):
            if title in self.books:
                self.books[title].available = True
    library = Library()
    library.add_book(Book(____))
    print(library.borrow_book(____))
    print(library.borrow_book(____))
    library.return_book(____)
    print(library.borrow_book(____))