Problem 875. Return a list sorted by number of consecutive occurrences

Created by Jean-Marie Sainthillier

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Inspired by Problem 38 by Cody Team. Given a vector x, return a vector y of the values in x sorted by the number of CONSECUTIVE occurrences in x. Ties (and it is the difficulty) are sorted from lowest to highest. So if x = [1 2 2 2 3 3 7 7 93] then
 y = [2 3 7 1 93]
But if x = [1 1 2 2 2 3 3 7 7 1 93] then
 y = [2 1 3 7 1 93]
Update - Test case added 22-8-22

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Last Solution submitted on Oct 26, 2025

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Jean-Marie Sainthillier on 13 Aug 2012

@bmtran is a too strong for me.

J.R.! Menzinger on 21 Feb 2014

I think that in case 3, the correct answer should be: y_correct1 = [1 0 2 9 1 -5 2 0 11] and in case 4: y_correct0 = [1 0 1 0], or did I misunderstood the goal?

Berkay Dogus on 1 Aug 2018

I agree with J.R.! Menzinger. Correct answers given are wrong.

goc3 on 2 Aug 2018

No, the provided answers in the test cases are correct. This is "the difficulty" that Jean-Marie mentions above: for integers that are tied by number of occurrences, they are to be sorted within the tied subset in ascending order, not kept in the original ordering within the vector.

Kleber Zuza Nobrega on 20 Apr 2021

Do you mind do explain in a different way? it is not clear for what exactly i should do. It miss 3 problems for me, but in any of them it is not clear the problem itself.

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Problem 875. Return a list sorted by number of consecutive occurrences

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Problem 875. Return a list sorted by number of consecutive occurrences

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