Changing direction

Changing direction


You are given a sequence of integers. Your task in this mission is to find, how many times the sorting direction was changed in the given sequence. If the elements are equal - the previous sorting direction remains the same, if the sequence starts from the same elements - look for the next different to determine the sorting direction.

Let's look at the scheme:


There are three sorting directions:

  • on the chunk 1, 2, 2 - up (increasing);
  • on the chunk 2, 1 - down (decreasing);
  • and on the chunk 1, 2, 2 - up again.
So, you have two points of changing the sorting direction: #1 - from up to down, and #2 - from down to up. That's the result your function should return.

Input: List of integers (int).

Output: An integer (int).


assert changing_direction([1, 2, 3, 4, 5]) == 0
assert changing_direction([1, 2, 3, 2, 1]) == 1
assert changing_direction([1, 2, 2, 1, 2, 2]) == 2


  • the sequence is non-empty;
  • the elements are positive integers.

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

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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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