# Name
# CSE 160
# Autumn 2025
# Coding Practice 4


# Problem 1
def average_pages():
    '''
    Write a function average_pages, that takes in a nested list
    of integers. Each list inside represents a book series, and each integer
    represents the number of pages in a book of that series. Determine
    the average number of pages per book series, and then append the 
    average for each series into a new list. Return the list of averages.
    DO NOT use Python's built-in sum() method!
    '''

    # Write your solution to Problem 1 here

'''
Example:

average_pages([[315, 427, 395],
		    [682, 590, 825],
		    [465, 546]]) returns [379.0, 699.0, 505.5]
'''


# Problem 2
def sort_books():
    '''
    Write a function sort_books, that takes in a nested list where the 
    first inner list is a list of books and the second is a list of their 
    genres in RESPECTIVE order. Return a dictionary that maps each book to its
    genre. You can assume that both inner lists will always have the 
    same number of items.
    '''

    # Write your solution to Problem 2 here

'''
Example:

sort_books([["Parable of the Sower", "Crying in H-Mart", "Sapiens"],
            ["Sci-Fi", "Memoir", "Non-fiction"]]) returns 
 {"Parable of the Sower": "Sci-Fi","Crying in H-Mart": "Memoir", "Sapiens": "Non-fiction"}

'''

# Problem 3
def count_genre():
    '''
    Write a function count_genre, that takes in a dictionary like the one
    sort_books returns and a String representing a given genre. Return the number of times
    that genre appears in the dictionary. The function should return None if no
    books of the given genre are present in the dictionary
    '''

    # Write your solution to Problem 3 here


'''
Examples:
dict = {"Crying in H-Mart": "Memoir",
	   "Glass Castle": "Memoir",
	   "Sapiens": "Non-fiction"}

count_genre(dict, "Memoir") returns 2
count_genre(dict, "Non-fiction") returns 1
count_genre(dict, "Fiction") returns None

'''