Problem 782. Some Assembly Required

Created by James

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","targetMode":"","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","targetMode":"","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>The input to this function is a matrix of real numbers. Your job is to assemble the rows of the matrix into one large row that contains all of the individual rows of the matrix, and to make this output row as short as possible. You accomplish this by joining the rows together at the points at which they overlap. To help with the task, you can flip rows if you need to do so.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>For example:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[input = [1 1 2 3 ; 4 5 6 7 ; 5 4 8 3]\n\noutput = [1 1 2 3 8 4 5 6 7]]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Explanation: The [1 1 2 3] is the first row of the input.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>[3 8 4 5] is the third row (flipped) so the 3 at the end of the third row overlaps with the 3 at the end of the first row.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>[4 5 6 7] is the second row, with the [4 5] overlapping with the flipped [5 4] from the third row.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Other than the mirrored version of the solution ([7 6 5 4 8 3 2 1 1] in the above example), each solution will be unique. Flipped versions of the entered value of y_correct will be tested for as well, in case your code comes up with that version of the correct answer.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Good luck, and happy hunting.</w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

The input to this function is a matrix of real numbers. Your job is to assemble the rows of the matrix into one large row that contains all of the individual rows of the matrix, and to make this output row as short as possible. You accomplish this by joining the rows together at the points at which they overlap. To help with the task, you can flip rows if you need to do so.For example:<pre class="language-matlab">input = [1 1 2 3 ; 4 5 6 7 ; 5 4 8 3]
</pre><pre class="language-matlab">output = [1 1 2 3 8 4 5 6 7]
</pre>Explanation:
The [1 1 2 3] is the first row of the input.[3 8 4 5] is the third row (flipped) so the 3 at the end of the third row overlaps with the 3 at the end of the first row.[4 5 6 7] is the second row, with the [4 5] overlapping with the flipped [5 4] from the third row.Other than the mirrored version of the solution ([7 6 5 4 8 3 2 1 1] in the above example), each solution will be unique. Flipped versions of the entered value of y_correct will be tested for as well, in case your code comes up with that version of the correct answer.Good luck, and happy hunting.

The input to this function is a matrix of real numbers.  Your job is to assemble the rows of the matrix into one large row that contains all of the individual rows of the matrix, and to make this output row as short as possible.  You accomplish this by joining the rows together at the points at which they overlap.  To help with the task, you can flip rows if you need to do so.

For example:

input  = [1 1 2 3 ; 4 5 6 7 ; 5 4 8 3]

output = [1 1 2 3 8 4 5 6 7]

Explanation:
The [1 1 2 3] is the first row of the input.

[3 8 4 5] is the third row (flipped) so the 3 at the end of the third row overlaps with the 3 at the end of the first row.

[4 5 6 7] is the second row, with the [4 5] overlapping with the flipped [5 4] from the third row.

Other than the mirrored version of the solution ([7 6 5 4 8 3 2 1 1] in the above example), each solution will be unique.  Flipped versions of the entered value of y_correct will be tested for as well, in case your code comes up with that version of the correct answer.

Good luck, and happy hunting.

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Solution Stats

507 Solutions
71 Solvers

Last Solution submitted on Jun 18, 2021

Last 200 Solutions

Problem Comments

6 Comments

6 Comments

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Tim on 22 Jun 2012

The 16 in test case 4 should be a 6.

James on 22 Jun 2012

It's changed now. Good catch.

Gunther S on 5 Jan 2018

FYI: at this moment all solutions below score 150 are hard-coded ones

James on 8 Jan 2018

I've added some randomness to the test suite questions to stop the look-up tables from working properly. Thanks for the heads up on that. As you may have noticed, it's been a while since I submitted this problem!

Daniel Bergman on 18 Jan 2019

Solutions aren't unique: f([1;2;3]) = {[1,2,3],[1,3,2],[2,1,3]}

Alexander on 12 Feb 2019

Nice problem!

Solution Comments

Solution 2077121

1 Comment

1 Comment

Chul Min Yeum on 2 Jan 2020

It's quite challenging!

Solution 298261

1 Comment

1 Comment

James on 8 Jan 2018

combvec is no longer usable in Cody? No more Neural Network toolbox, I guess.

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Problem Tags

assembly matrix manipulation

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