Problem 1024. Doubling elements in a vector

Given the vector A, return B in which all numbers in A are doubling. So for:

A = [ 1 5 8 ]

then

B = [ 1 1 5 5 8 8 ]

Solve

Last Solution submitted on Apr 20, 2025

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srisai vangara on 29 Apr 2020

Really found a lot of trouble to find the solution.
But could not find how someone could solve it just using a size of 7.

Sivaramarao B on 7 Jun 2020

good one

Kaiz Merchant on 4 Aug 2020

What matlab functions are useful for this ? (I did it with a loop)

Michael Green on 8 Feb 2021

Good problem if you don't use repelem

Javid Moraveji on 4 Jun 2022

I think the test should also check for column vectors and any vector with special variables Inf and NaN

Mostafa on 30 Dec 2022

Nice problem without using kron function

James Baker on 8 Jan 2024

B = [ A A];
Is a valid answer! Your problem statement says nothing about the element in vector b being in order. Test 2 is correct for only one case.

Bhavik on 17 Feb 2024

Use repelem inbuilt function

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