Problem 40. Reverse Run-Length Encoder

Created by科迪Team

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{"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>Given a \"counting sequence\" vector x, construct the original sequence y.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>A counting sequence is formed by \"counting\" the entries in a given sequence. This is sometimes called run-length encoding.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>For example, the sequence</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[ x = 2, 5, 1, 2, 4, 1, 1, 3]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>can be read as</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[ Two 5's, one 2, four 1's, one 3]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>which translates to</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[ y = 5, 5, 2, 1, 1, 1, 1, 3]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>So y is the reconstructed vector that corresponds to the counting sequence x.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>For this problem, all elements in the sequences x and y will be in the range from 1 to 9.</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>"}]}

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Solution Stats

3119 Solutions
1974 Solvers

LastSolutionsubmitted on May 25, 2022

Last 200 Solutions

Problem Comments

4 Comments

4 Comments

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卡尔Witthofton 17 Nov 2015

看到我的函数“seqle”文件Exchange. It may not be as compact, but it's easy to use and both encodes and decodes.

David Verrelli2017年9月28日

The problem statement would have been clearer if the principle of RLE had been explained with an encoding example first. Alternatively, it would have been useful to explicitly mention that the data in vector x is being read pairwise.

Sanzhar Askarulyon 5 Jul 2019

easy

subbarao sathaon 2 Mar 2020

useful challenge

Solution Comments

Solution 2177272

1 Comment

1 Comment

Tommyon 27 Mar 2020

ugly but more fun than loops!

Solution 668373

1 Comment

1 Comment

Alfonso Nieto-Castanonon 9 May 2015

note: repelem did not exist back when this problem was created

Solution 550698

1 Comment

1 Comment

Diegoon 30 Dec 2014

not limited to 1-9

Solution 529550

2 Comments

2 Comments

Adr Pawon 11 Aug 2016

This is my favourite

DJHuangon 2 Mar 2020

NICE

Solution 54224

2 Comments

2 Comments

Jonon 4 Dec 2013

Best score without regexp

bainhome2015年5月8日

agree,great indeed!

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