Problem 32. Most nonzero elements in row

Created by Cody Team

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 the matrix a, return the index r of the row with the most nonzero elements. Assume there will always be exactly one row that matches this criterion.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Example:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[ Input  a = [ 1 2 0 0 0\n              0 0 5 0 0 \n              2 7 0 0 0\n              0 6 9 3 3 ]\n Output r is 4]]></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

18151 Solutions
6692 Solvers

Last Solution submitted on Jan 27, 2023

Last 200 Solutions

Problem Comments

11 Comments

11 Comments

Show 8 older comments

Rodolfo on 12 Mar 2013

How am I wrong here?
"a = [ ...
1 0 0;
0 0 0;
0 0 0;
0 0 0;
0 2 3];
r_correct = 5;"
My code says 2, I think it's correct, what am I missing?

Tim on 12 Mar 2013

It wants the number of the row with the most nonzeros.

Rodolfo on 12 Mar 2013

Thank you Tim! I feel like a fool, but that'll teach me to read the requirements more carefully. Hopefully.

Gabor Levai on 8 Sep 2016

Great Problem!

MEI HUEI LIM on 5 Jan 2017

nice

DilRavsh on 20 Aug 2017

Love this one

Basil C. on 19 Feb 2018

Piece of cake

Gani on 8 Feb 2019

nice

Alexander on 12 Feb 2019

easy :) but nice

Rahul Gulia on 20 Jul 2020

Could you please check my solution.
How come the solution example 2, 3 and 4 have r= 3, 5 and 4. When it should have been r = 4, 3 and 1.
As these are the maximum number of zeros in any of the given row.

Can someone please give me a hint on how the solutions are provided so different?

Rubeena Aafreen on 22 Oct 2020

What are these matrices in last 3 test cases? Can someone help

Solution Comments

Solution 9598438

1 Comment

1 Comment

wenyue hu on 25 Oct 2022

This problem is not difficult. But we still need to be careful

Solution 5883225

2 Comments

2 Comments

Shubham Kalra on 2 Jun 2021

Nice solution!

Hannah Callihan on 2 May 2022

nice solution!!

Solution 1826790

1 Comment

1 Comment

Olivia Li on 26 May 2019

so happy~

Solution 1654840

2 Comments

2 Comments

BAOHUA ZHANG on 22 Oct 2018

there is a bug i the code
input a = [1 0 1 1 ; 9999 0 0 0]
output 2

BAOHUA ZHANG on 22 Oct 2018

there is a bug in the code
input a = [1 0 1 1 ; 9999 0 0 0]
output 2

Solution 1640035

Solution 1474713

1 Comment

1 Comment

Ravi on 30 Mar 2018

r = max(sum((a==0)'));

Solution 1230250

1 Comment

1 Comment

Dustin Jones on 12 Jul 2017

Original solution I created by digging through documentation was x=a~=0; y=sum(x,2); [M,I]=max(y); r=max(y). Solution had a size of 31 so I compressed it into it's current version.

Solution 1198064

1 Comment

1 Comment

Jagdish Khatri on 26 May 2017

in case number 3 and 4 total number of element is also less than your correct fullest row output
How does this thing is possible

Solution 1102023

1 Comment

1 Comment

Yoshimasa Nakatani on 11 Jan 2017

I did it!
(^^;)

Solution 1029229

1 Comment

1 Comment

Dan Po on 24 Oct 2016

this is a terrible solution, someone help.

Solution 853944

1 Comment

1 Comment

Marilyn Elizabeth on 21 Mar 2016

Could you tell me how you did it?

Solution 695873

1 Comment

1 Comment

Nicholas Hortance on 4 Jul 2015

Once again ive used a for loop only because it seems so much simpler. The more I do these I see how each person has a different approach to a problem which I think is very cool. Thanks for the problem!

Solution 672510

1 Comment

1 Comment

Riazul Arefin on 20 May 2015

test suite is not ok

Solution 473067

2 Comments

2 Comments

SAMET YILDIZ on 15 Jul 2014

what is the problem here ? it works on matlab and gives the correct row

Tim on 24 Aug 2014

2 things: You forgot to set your output (so add a line r=ix, or change the r in the first line into ix.
and you changed the function name so it doesn't recognize it.

Your solution does work.

Solution 419193

1 Comment

1 Comment

Wesley Allen on 18 Mar 2014

Well done.

Solution 402540

2 Comments

2 Comments

Karthik Raja Arumugam on 12 Feb 2014

Is there any way to avoid this for loop??

Jörg on 20 May 2014

Yes, a hint: compare with zeros matrix and count (sum) the nonzero elements in this logical matrix.

Solution 313572

1 Comment

1 Comment

Gregor Baiker on 1 Sep 2013

looks very strange

Solution 39915

2 Comments

2 Comments

Alex Feinman on 13 Feb 2012

I can't believe I used a trick I learned from Javascript...

Swapnali Gujar on 8 Aug 2013

I tried to optimize my solution as much possible as I could, still my code size was 45, any idea what would be there in the leading solution of this problem which has code size as 11 ? Which trick did you use?

Problem Recent Solvers6692

Problem Tags

Community Treasure Hunt

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

Start Hunting!

Problem 32. Most nonzero elements in row

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers6692

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Problem 32. Most nonzero elements in row

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers6692

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Players