Problem 695. Parse string and identify specific string sequence in algebraic equation

Created by Siva

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","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\"?><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 string S that defines an algebraic expression such as:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>S= 'X= A1 + A2*(Y1 + A3*Y3)*exp( A4*Y12 + Y1) ;'</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>return a cell array {'Y1', 'Y12', 'Y123'}</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/><w:jc w:val=\"left\"/></w:pPr><w:r><w:t>i.e. parse the string S and identify the unique variables in the expression that start with the letter \"Y\".</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>"}]}

Solve

Solution Stats

132 Solutions
47 Solvers

Last Solution submitted on Dec 31, 2020

Last 200 Solutions

Problem Comments

1 Comment

1 Comment

Richard Zapor on 1 Jun 2012

I think the correct example solution is {'Y1', 'Y12', 'Y3'}.

Solution Comments

Solution 857811

1 Comment

1 Comment

William on 28 Mar 2016

Good exercise. Two comments: 1) test case 3 has unbalanced parentheses. 2) Instruction should say that your are expecting results to be returned in sorted order, rather than the order in which they appear in the expression.

Problem Recent Solvers47

Problem Tags

parser regexp string

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!