cheapest_options

Cheapest Options

Coding challenge for a job opening. Given a list of dates, provide the cheapest option according to the client type.

Challenge:

• Full description of the problem here

• Full description of the solution here

• Code originally written in 2019.

• Test cases added in 2019.

Test Execution

[user@user cheapest_options]$ python3 -m unittest discover -s tests
..........................................
----------------------------------------------------------------------
Ran 43 tests in 0.002s

OK

Coverage report

[user@user cheapest_options]$ coverage report

Name                             Stmts   Miss  Cover
----------------------------------------------------
constants.py                         1      0   100%
enums/__init__.py                    0      0   100%
enums/client.py                      4      0   100%
enums/stars.py                       5      0   100%
helpers/helpers.py                  40      0   100%
main.py                             29     15    48%
models/__init__.py                   0      0   100%
models/establishment.py             25      1    96%
models/input_processor.py           16      1    94%
models/price.py                     36      0   100%
models/reservation_date.py          13      0   100%
tests/__init__.py                    0      0   100%
tests/test_establishment.py         41      1    98%
tests/test_helpers.py               70      1    99%
tests/test_input_processor.py       40      1    98%
tests/test_main.py                  14      1    93%
tests/test_price.py                 25      1    96%
tests/test_reservation_date.py      22      1    95%
----------------------------------------------------
TOTAL                              381     23    94%

Problem

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A hotel chain wants to offer an online booking service. The chain is made up of establishments in three categories: Economy, Medium, and Luxury. Each establishment has different rates for weekdays and weekends, including specific rates for loyalty program participants. Additionally, each establishment has a rating indicating the quality of service.

• Economy has a rating of 3 and its weekday rates are R$ 110 for regular customers and R$ 80 for loyalty program participants. Weekend rates are respectively R$ 90 and R$ 80 for regular customers and loyalty program participants.
• Medium has a rating of 4 and its weekday rates are R$ 160 for regular customers and R$ 110 for loyalty program participants. Weekend rates are respectively R$ 60 and R$ 50 for regular customers and loyalty program participants.
• Luxury has a rating of 5 and its weekday rates are R$ 220 for regular customers and R$ 100 for loyalty program participants. Weekend rates are respectively R$ 150 and R$ 40 for regular customers and loyalty program participants.

Write a program to find the cheapest hotel. The program input will be a sequence of dates for regular customers or loyalty program participants. Use "Regular" to denote a regular customer and "Reward" to denote a customer participating in the loyalty program. The output should be the cheapest available hotel and, in case of a tie, the hotel with the highest rating should be returned.

Format of input:

<type_of_customer>: , , , ...

Format of output:

<name_of_cheapest_hotel>

---

Samples:

Input 1:

Regular: 16Mar2009(mon), 17Mar2009(tues), 18Mar2009(wed)

Output 1:

Economy

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Input 2:

Regular: 20Mar2009(fri), 21Mar2009(sat), 22Mar2009(sun)

Output 2:

Medium

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Input 3:

Rewards: 26Mar2009(thur), 27Mar2009(fri), 28Mar2009(sat)

Output 3:

Luxury

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Solution

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Running the Application

Requirements:

• Python 3.6+

Run from the "cheapest_options" directory:

$ python3 main.py ${INPUT_FILE}

Example:

$ python3 main.py "samples/sample_data.txt"

To run the tests, from the "cheapest_options" directory:

$ python3 -m unittest discover -s tests

Assumptions:

• The customer type (Regular or Rewards) will not be blank;
• The list of dates does not necessarily have a limit (past or future), nor do they need to be in chronological order, as long as they are valid dates;
• The weekend is considered to be Saturday and Sunday only; the total price should aggregate values for different types of days, as applicable (it doesn’t assume the highest or lowest value);
• The input file will have a limited size, and the program will run on a computer with sufficient resources to process it adequately. Continuous input, such as a log file being written to while processing, was not considered.

Application Design:

The entry point is created in the main.py module, which sets up and handles file input. From this point, the run() function is called for each line of input, executing the following application flow:

• InputProcessor parses the line, separating the string with the customer type from the list of date strings for the reservation;
• ReservationDate converts date strings into datetime objects and calculates information about the dates, such as the number of weekdays, weekends, and the length of stay;
• It records whether the customer is Rewards or Regular;
• Price organizes prices, instantiating categories of establishments according to the dates and customer type for the reservation;
• The Establishment class provides information on which rate should be considered based on the type of date, customer, and establishment category.
• Based on the processed information, the output is returned as the name of the cheapest establishment.

Additionally:

• Helpers: module with support functions, more generic and reusable in the future;
• Enums: used for values that don’t change necessarily and don’t need extensive logic;
• Constants: module with application constants, including the price table formatted as a dictionary—although it’s mutable, the intent is to abstract these details from the application and emulate a non-relational database.

Application Execution:

[user@user cheapest_options]$ python3 main.py "samples/sample_data.txt"
Economy
Medium
Luxury