Problem 60994. Cumulative Count

Created by Dyuman Joshi

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Given a row vector of integers with repeating values (with all repeating values occuring in a single continuous run), create an array that is the cumulative count of the unique values - 
%% Example 1
input = [4 5 5 6 11 11 11 11 20 20 20 20 20 20 20 35 50 50];
output = [1 1 2 1 1 2 3 4 1 2 3 4 5 6 7 1 1 2];
%% Example 2
input = [33 33 33 22 22 11];
output = [1 2 3 1 2 1];
Only vectorized solutions will be accepted. Check the test suite for banned functions.

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9 Solutions
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Last Solution submitted on Sep 15, 2025

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3 Comments

Christian Schröder on 5 Sep 2025 at 13:17

Cool problem! For the benefit of those who have yet to solve it, you don't need to "remember" the counts of each element, so [4 5 5 6 5 5] should yield [1 1 2 1 1 2] and not [1 1 2 1 3 4].

Dyuman Joshi on 5 Sep 2025 at 15:25

Thank you Christian!

FYI - Such cases aren't included in the scope of this problem.
I have updated the Problem description to make the statement more precise.

Though they will be considered for upcoming variations of this problem!

Christian Schröder on 5 Sep 2025 at 19:50

Thanks, Duyman. I have a solution for that case too. Unfortunately submitting problems to Cody appears to be broken right now, which I only realized AFTER creating a new one.

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Problem 60994. Cumulative Count

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Problem 60994. Cumulative Count

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Last 200 Solutions

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Problem Recent Solvers6

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