Problem 722. Make a run-length companion vector

Created by Ned Gulley

Solve Later

Given a vector x, return a vector r that indicates the run length of any value in x. Each element in r shows how many times the corresponding element in x has appeared consecutively.

Example:

 Input  x = [5 3 3 1 0 9 9 4 4 4 4 5 1 2 2]
 Output r = [1 1 2 1 1 1 2 1 2 3 4 1 1 1 2]

Solve

Solution Stats

967 Solutions
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Last Solution submitted on Jan 09, 2020

Last 200 Solutions

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5 Comments

5 Comments

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Wenwu on 4 Jan 2015

The first test case seems to be invalid answer. Please check it

Ned Gulley on 6 Jan 2015

Hi Wenwu: Could you be more specific about what you think the problem is?

Carl Witthoft on 9 Dec 2015

See FileExchange's seqle . (disclaimer: I'm the author)

hubert andre on 13 Apr 2016

False exemple description

GEORGIOS BEKAS on 14 Feb 2018

y=[];

for i = 1:length(delta)
test = max(delta(1:i));
maxsofar=max(delta(1:i-1));
test2=min(delta(1:i));
minsofar=min(delta(1:i-1));
if test == delta(i) && delta(i)~= maxsofar
y=[y,1];
elseif test2 == delta(i) && delta(i)~= minsofar
y=[y,-1];
else
y=[y,0];
end
end

this code despite its giving correct results it is rejected by the tests...

Solution Comments

Solution 1088822

1 Comment

1 Comment

cool on 24 Dec 2016

the 1st test suite seems not right.

Solution 815614

1 Comment

1 Comment

ABDELRAHMAN on 28 Jan 2016

the sol of first test isn't correct

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Problem 722. Make a run-length companion vector

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Problem 722. Make a run-length companion vector

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