"Lunar" Multiply

"Lunar" Multiply

Simple+
DE English FR PL UK ZH-HANS

This problem was inspired by another jovial Numberphile video “Primes on the Moon” by Neil Sloane that you should watch first to get an idea of how this wacky “lunar arithmetic” works.

Formerly known as “dismal arithmetic”, addition and multiplication of natural numbers are redefined so that adding two digits means taking their maximum, whereas multiplying two digits means taking their minimum. For example, 2 + 7 = 7 + 2 = 7 and 2 × 7 = 7 × 2 = 2. Unlike ordinary addition, there can never be a carry to the next column of digits, no matter how many individual digits are added together in that column. For numbers that consist of several digits, addition and multiplication work exactly as you learned back in grade school, except that the shifted digit columns from lunar multiplication of the individual digits are added in the same lunatic fashion. Let's look again at the example:

example

Input: Two integers (int).

Output: Integer (int).

Examples:

assert lunar_multiply(2, 3) == 2
assert lunar_multiply(8, 9) == 8
assert lunar_multiply(10, 10) == 100
assert lunar_multiply(11, 11) == 111

The mission was taken from Python CCPS 109. It is taught for Ryerson Chang School of Continuing Education by Ilkka Kokkarinen

Settings
Code:
Other:
Invalid hot key. Each hot key should be unique and valid
Hot keys:
CheckiO Extensions

CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.

In order to install CheckiO client you'll need installed Python (version at least 3.8)

Install CheckiO Client first:

pip3 install checkio_client

Configure your tool

checkio --domain=py config --key=

Sync solutions into your local folder

checkio sync

(in beta testing) Launch local server so your browser can use it and sync solution between local file end extension on the fly. (doesn't work for safari)

checkio serv -d

Alternatevly, you can install Chrome extension or FF addon

checkio install-plugin
checkio install-plugin --ff
checkio install-plugin --chromium

Read more here about other functionality that the checkio client provides. Feel free to submit an issue in case of any difficulties.

Pair Programming (Beta-version)

Welcome to Pair Programming! Engage in real-time collaboration on coding projects by starting a session and sharing the provided unique URL with friends or colleagues. This feature is perfect for joint project development, debugging, or learning new skills together. Simply click 'Start Session' to begin your collaborative coding journey!

Waiting for Pair Programming to start...

You are trying to join a pair programming session that has not started yet.

Please wait for the session creator to join.

Waiting for Pair Programming to reconnect...

It looks like the creator of the pair programming session closed the editor window.

It might happen accidentally, so that you can wait for reconnection.

×
 
 
<< <
> >>
exec show

Whats Next?

Free accounts will see Best CheckiO solutions with some delay.
Best Solutions will be opened in a moment
Become Awesome and Don't wait
The next stage is ""
Will be activated in
View More Solutions Random Review Solutions Go to the next mission