Problem 32. Most nonzero elements in row

Created by Cody Team

Solve Later

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.

Example:

 Input  a = [ 1 2 0 0 0
              0 0 5 0 0 
              2 7 0 0 0
              0 6 9 3 3 ]
 Output r is 4

Solve

Solution Stats

19236 Solutions
7376 Solvers

Last Solution submitted on May 17, 2025

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

Show comments

Problem Recent Solvers7376

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 Solvers7376

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 Solvers7376

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Players