def return_book(s, books, users):
# return book function receive the user command 's' and the arrays 'books' and 'users' and removes the book borrowed
# complexity is O(1)
j = hash_actions.hash_search(
books, s[2][2:]
) # find book using hash search, sending only 4 digit part of book id
books[j] = None # updates books array
h = hash_actions.hash_search(users, s[1]) # find the user returning index
users[h].remove(s[2]) # update user record, remove the book returned
return books, users
def books_check(s, users):
# books check function checks weather or not the user already borrowing 10 books, complexity is O(1)
j = hash_actions.hash_search(users, s[1])
if len(users[j]) > 11:
return True
else:
return False
def borrow_book(s, books, users):
# borrow book function receive the user command 's' and the arrays 'books' and 'users' and updates them with the
# new book borrowed, complexity is O(1)
j = hash_actions.hash_insert(books, int(
s[2]
[2:])) # calling 'hash insert' function to insert book, sending only
# the 4 digit number part of the book id for open addressing algorithm
books[j] = [s[2], s[1],
s[0]] # update 'books' array with the new book borrowed
h = hash_actions.hash_search(users, s[1]) # find the user borrowing index
users[h].append(s[2]) # update user record with the book borrowed
return books, users
def find_user(s, users):
# find user function for the '? USER_ID' query, receive user command 's' and users array and returns the user name
# and id and list of books which they are currently borrowing, complexity is O(1)
j = hash_actions.hash_search(users, s[1])
return users[j][1], users[j][0], users[j][2:]
def remove_user(s, users):
# remove user function receive the user command 's' and the arrays 'users' and removes the user, complexity is O(1)
j = hash_actions.hash_search(users, s[2])
users[j] = None
return users
def find_book(s, books):
# find book function for the '? BOOK_ID' query, receive user command 's' and books array and returns the user name
# and id which is currently holding the book, complexity is O(1)
j = hash_actions.hash_search(books, s[1])
return books[j][1], books[j][2]