Count Chains

Count Chains


In this mission you must count chains.

You are given a list of details of the circle (tuple of X-coordinate, Y-coordinate, radius).
You have to return the number of groups of circles where their circumferences intersect.


Only one circle counts as one group.


count_chains([(1, 1, 1), (4, 2, 1), (4, 3, 1)]) == 2
count_chains([(1, 1, 1), (2, 2, 1), (3, 3, 1)]) == 1
count_chains([(1, 1, 1), (1, 3, 1), (3, 1, 1), (3, 3, 1)]) == 4


  • A list of details of the circle.
  • Details of the circle is a tuple of three integers(X-coordinate, Y-coordinate, radius).

Output: An integer.


  • -10 ≤ x(, y) coordinate ≤ 10
  • 1 ≤ radius ≤ 10

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.

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