Problem 924. intersection of matrices

Created by Richard

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>Given two matrices filled with ones and zeros, determine if they share a common row, column entry. These matrices are of identical size.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Examples:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[Inputs A = [1 0 0 0 0\n 0 1 0 0 0\n 0 0 1 0 0\n 0 0 0 1 0\n 0 0 0 0 1 ] \n\n and B = [0 1 0 0 0\n 0 0 1 0 0\n 0 0 0 1 0\n 0 0 0 0 1\n 1 0 0 0 0 ]\n\nOutput tf is false\n\nInputs A = [1 1 1 0 1\n 1 1 1 1 0\n 0 1 1 1 1\n 1 0 1 1 1\n 1 1 0 1 1 ]\n and B = [0 1 0 0 0\n 1 0 0 0 0\n 0 0 0 0 1\n 0 0 0 1 0\n 0 0 1 0 0]]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Output tf is true</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>"}]}

Given two matrices filled with ones and zeros, determine if they share a common row, column entry. These matrices are of identical size.Examples:<pre class="language-matlab">Inputs A = [1 0 0 0 0
 0 1 0 0 0
 0 0 1 0 0
 0 0 0 1 0
 0 0 0 0 1 ] 
</pre><pre> and B = [0 1 0 0 0
 0 0 1 0 0
 0 0 0 1 0
 0 0 0 0 1
 1 0 0 0 0 ]</pre><pre class="language-matlab">Output tf is false
</pre><pre class="language-matlab">Inputs A = [1 1 1 0 1
 1 1 1 1 0
 0 1 1 1 1
 1 0 1 1 1
 1 1 0 1 1 ]
 and B = [0 1 0 0 0
 1 0 0 0 0
 0 0 0 0 1
 0 0 0 1 0
 0 0 1 0 0]
</pre>Output tf is true

Solve

Solution Stats

1025 Solutions
347 Solvers

Last Solution submitted on Jan 19, 2021

Last 200 Solutions

Problem Comments

6 Comments

6 Comments

Show 3 older comments

Marcel on 31 Dec 2013

I guess zeros are not included as common elements.

Elmar Zander on 3 Mar 2017

Yes. Seems to be a somewhat "ill-posed" problem...

Andrew Newell on 18 Apr 2017

What does "they share a common row, column entry" mean?

Nanfei Cheng on 23 Sep 2020

I think it should be a non-zero common row, column entry.

Chien-Han Su on 4 Nov 2020

Just consider the problem to be "Is there any i, j such that A(i,j) == B(i,j) == 1"

Jeong Suong Yang on 9 Nov 2020

I guess it means intersection of arrays, literally.

Solution Comments

Solution 4621039

1 Comment

1 Comment

Qin-Yong on 19 Jan 2021 at 5:50

tf=any(ismember([A(:)==1 B(:)==1],[1 1],'rows'));

Solution 2984500

Solution 1302071

1 Comment

1 Comment

Li Ding on 19 Oct 2017

Re-wording is needed for this problem. Here is how I interpreted the problem:
1. "common row, column entry" means a same value at the same row-column location
2. zeros don't count. You need to check for non-zeros...

Problem Recent Solvers347

Problem Tags

matrix poor_problem_statement

Community Treasure Hunt

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

Start Hunting!