Lab Assignment #8 Solution

Assignment Objectives




This lab assignment will give you some practice with dictionaries and lists.




Getting Started




Visit Piazza and download the “bare bones” file lab8.py onto your computer. Open lab8.py in PyCharm and fill in the following information at the top:




1. your first and last name as they appear in Blackboard




2. your Net ID (e.g., jsmith)




3. your Stony Brook ID # (e.g., 111999999)




4. the course number (CSE 101)




5. the assignment name and number (Lab #8)




Submit your final lab8.py file to Blackboard by the due date and time. Late work will not be graded. Code that crashes and cannot be graded will earn no credit.




Preliminaries




In this lab you will be writing functions that manage rooms at a hotel. We will be using the following room types:




• Normal




• Double




• King




• Suite










Part I: Vacation Cost Calculator (20 points)




You are a travel agent and have been tasked with making reservations for a large group of people with a fixed budget staying at a resort hotel for a week. Each kind of room (Normal, Double, King, Suite) has a fixed price to rent for the week.




Complete the function vacation calculator that takes arguments in the following order:

1. room prices: A dictionary that maps a type of room (a string) to the price of the room (an integer).




2. budget: An integer value that represents the maximum amount of money the group will spend for the hotel stay.




3. reservations: A list of sub-lists wherein the first element of a sub-list contains the type of room being reserved, and the second element is the desired count of rooms of that type. For example, the sub-list [’King’, 3] would indicate that 3 King rooms are desired.




The function iterates over the reservations list, extracting the room type and room count of each reservation. Room types can appear multiple times in the list. Then, the function looks up the price of the desired room using the room prices dictionary and computes what it would cost to reserve the desired number of rooms. You may assume that the room type in the reservation always has a corresponding price in room prices. If there is money left in the budget to accept the reservation, the function (i) appends the sub-list to a result list and (ii) subtracts the cost of the reservation from the budget. If a certain reservation in reservations list does not fit within the remaining budget, the function skips over that reservation and moves on to the next one in the list.




At the end, the function returns two values in a tuple: the total spent on the vacation, followed by the list of reservations that were accepted by the resort.




Examples:




Function Call
Return Values
vacation calculator({’Normal’: 70, ’Double’:

105, ’King’: 195, ’Suite’: 249}, 543, [[’Normal’, 1], [’Suite’, 2], [’Double’, 2], [’Normal’, 1], [’King’, 3]])
(350, [[’Normal’,

1], [’Double’, 2], [’Normal’, 1]])
vacation calculator({’Normal’: 72, ’Double’:

133, ’King’: 192, ’Suite’: 246}, 255, [[’King’,

3], [’Suite’, 1], [’King’, 1], [’Normal’, 1], [’King’, 2], [’Double’, 3], [’Suite’, 3]])
(246, [[’Suite’, 1]])
vacation calculator({’Normal’: 85, ’Double’:

148, ’King’: 190, ’Suite’: 239}, 319, [[’Suite’,

1], [’Double’, 1], [’Normal’, 2], [’Double’, 2], [’Double’, 2], [’Suite’, 2]])
(239, [[’Suite’, 1]])
vacation calculator({’Normal’: 99, ’Double’:

104, ’King’: 194, ’Suite’: 275}, 516, [[’Normal’, 3], [’King’, 2], [’Suite’, 2], [’Normal’, 3], [’Suite’, 2], [’Double’, 1]])
(401, [[’Normal’, 3],

[’Double’, 1]])
vacation calculator({’Normal’: 90, ’Double’:

119, ’King’: 158, ’Suite’: 287}, 648, [[’King’,

2], [’Double’, 1], [’Double’, 3], [’King’, 3], [’Double’, 1]])
(554, [[’King’,

2], [’Double’, 1], [’Double’, 1]])
vacation calculator({’Normal’: 98, ’Double’:

132, ’King’: 169, ’Suite’: 220}, 225, [[’King’,

1], [’King’, 2], [’King’, 2], [’King’, 3], [’Double’, 3], [’Double’, 1]])
(169, [[’King’, 1]])



vacation calculator({’Normal’: 91, ’Double’:

113, ’King’: 181, ’Suite’: 243}, 331, [[’Suite’,

3], [’Double’, 3], [’Double’, 2], [’Double’, 3]])
(226, [[’Double’, 2]])
vacation calculator({’Normal’: 76, ’Double’:

124, ’King’: 173, ’Suite’: 291}, 0, [[’Double’,

1], [’King’, 2], [’Double’, 2]])
(0, [])
vacation calculator({’Normal’: 78, ’Double’:

148, ’King’: 183, ’Suite’: 213}, 541, [])
(0, [])
vacation calculator({’Normal’: 61, ’Double’:

115, ’King’: 196, ’Suite’: 212}, 0, [])
(0, [])









Part II: Let Me Inn (20 points)




You are the manager of the Let Me Inn. A travel agent has sent you a list of reservations that can be accommodated by the hotel. Your primary job is to send him back the total cost of the reservations. To make sure your hotel runs properly, you also will keep track of how much money you have made from each type of room (Normal, Double, King, Suite).




Complete the function hotel manager which takes arguments in the following order:




1. room prices: A dictionary that maps a type of room (a string) to the price of the room (an integer).




2. room counts: A dictionary that maps a type of room (a string) to the number of available rooms of that type (an integer).




3. reservations: A list of sub-lists wherein the first element of a sub-list contains the type of room being reserved, and the second element is the desired count of rooms of that type. For example, the sub-list [’King’, 3] would indicate that 3 King rooms are desired.




The function iterates over the reservations list, extracting the room type and room count of each reservation. Room types can appear multiple times in the list. Then, the function looks up the price of the desired room using the room prices dictionary and determines what it would cost to reserve the desired number of rooms. You may assume that the room type in the reservation always has a corresponding price in room prices and a corresponding count in room counts.




If there are enough available rooms to accept the reservation, the function (1) updates the total income generated by the reservation, (2) updates room counts to reflect that fewer rooms are now available, and (3) updates a dictionary that tracks how much income was generated by each type of room. As an example, suppose that a King room costs $200 per night and 3 have such rooms been successfully reserved. Suppose also that we have created a dictionary called room incomes to store the income generated by each room type. In this example, the function would add 600 both to room incomes[’King’] and to the total income generated. It would also subtract 3 from room counts[’King’].




If a certain reservation in reservations list cannot be accommodated due to a shortage of rooms, the function skips over that reservation and moves on to the next one in the list.




At the end, the function returns two values in a tuple: the total income generated by the accepted reservations, followed by the updated room incomes dictionary.

Examples:




Function Call
Return Values
hotel manager({’Normal’: 70, ’Double’: 105,

’King’: 195, ’Suite’: 249}, {’Normal’: 13,

’Double’: 9, ’King’: 5, ’Suite’: 3}, [[’Suite’,

1], [’King’, 3], [’Double’, 6], [’King’, 5], [’King’, 3], [’King’, 5]])
(1464, {’Suite’:

249, ’King’: 585,

’Double’: 630})
hotel manager({’Normal’: 79, ’Double’: 101,

’King’: 190, ’Suite’: 270}, {’Normal’: 12,

’Double’: 7, ’King’: 7, ’Suite’: 3}, [[’King’,

4], [’Double’, 7], [’Suite’, 2]])
(2007, {’King’: 760,

’Double’: 707,

’Suite’: 540})
hotel manager({’Normal’: 60, ’Double’: 128,

’King’: 178, ’Suite’: 226}, {’Normal’: 11,

’Double’: 8, ’King’: 5, ’Suite’: 4}, [[’Suite’,

1], [’King’, 5], [’Suite’, 2], [’Normal’, 9]])
(2108, {’Suite’:

678, ’King’: 890,

’Normal’: 540})
hotel manager({’Normal’: 78, ’Double’: 106,

’King’: 193, ’Suite’: 239}, {’Normal’: 12,

’Double’: 10, ’King’: 6, ’Suite’: 3}, [[’Suite’, 3], [’Double’, 5], [’King’, 3], [’Suite’, 2], [’King’, 4], [’Double’, 5], [’Double’, 7]])
(2356, {’Suite’: 717,

’Double’: 1060,

’King’: 579})
hotel manager({’Normal’: 97, ’Double’: 144,

’King’: 185, ’Suite’: 242}, {’Normal’:

11, ’Double’: 7, ’King’: 7, ’Suite’: 4}, [[’Normal’, 10], [’King’, 3], [’King’, 4], [’King’, 4]])
(2265, {’Normal’:

970, ’King’: 1295})
hotel manager({’Normal’: 73, ’Double’: 145,

’King’: 160, ’Suite’: 295}, {’Normal’: 11,

’Double’: 8, ’King’: 7, ’Suite’: 3}, [[’King’,

5], [’Double’, 5], [’Suite’, 1], [’Double’, 6], [’Double’, 7], [’Suite’, 3]])
(1820, {’King’: 800,

’Double’: 725,

’Suite’: 295})
hotel manager({’Normal’: 73, ’Double’: 145,

’King’: 162, ’Suite’: 215}, {’Normal’:

11, ’Double’: 7, ’King’: 6, ’Suite’: 4}, [[’Normal’, 11], [’Normal’, 11], [’Suite’, 1], [’Suite’, 1], [’Double’, 7], [’Double’, 5], [’Suite’, 0]])
(2248, {’Normal’:

803, ’Suite’: 430,

’Double’: 1015})
hotel manager({’Normal’: 62, ’Double’: 100,

’King’: 164, ’Suite’: 252}, {’Normal’: 0,

’Double’: 0, ’King’: 0, ’Suite’: 0}, [])
(0, {})
hotel manager({’Normal’: 60, ’Double’: 124,

’King’: 155, ’Suite’: 296}, {’Normal’: 12,

’Double’: 8, ’King’: 5, ’Suite’: 4}, [])
(0, {})
hotel manager({’Normal’: 60, ’Double’: 107,

’King’: 155, ’Suite’: 299}, {’Normal’: 0,

’Double’: 0, ’King’: 0, ’Suite’: 0}, [])
(0, {})






CSE 101 – Spring 2018 Lab #8 Page 4

How to Submit Your Work for Grading




To submit your .py file for grading:




1. Login to Blackboard and locate the course account for CSE 101.




2. Click on “Assignments” in the left-hand menu and find the link for this assignment.




3. Click on the link for this assignment.




4. Click the “Browse My Computer” button and locate the .py file you wish to submit. Submit only that one

.py file.




5. Click the “Submit” button to submit your work for grading.







Oops, I messed up and I need to resubmit a file!




No worries! Just follow the above directions again. We will grade only your last submission.

















































































































































CSE 101 – Spring 2018 Lab #8 Page 5