Problem 838. Check if number exists in vector

Created by Nichlas

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>Return 1 if number</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:i/></w:rPr><w:t>a</w:t></w:r><w:r><w:t> exists in vector</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:i/></w:rPr><w:t>b</w:t></w:r><w:r><w:t> otherwise return 0.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[a = 3;\nb = [1,2,4];]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Returns 0.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[a = 3;\nb = [1,2,3];]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Returns 1.</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

15954 Solutions
7262 Solvers

Last Solution submitted on May 21, 2022

Last 200 Solutions

Problem Comments

7 Comments

7 Comments

Show 4 older comments

Richard Zapor on 17 Jul 2012

Add test vector a = -12;
b = [1,3,4,5,6,7,8,-12,2]; and rescore.
Better is add a=-randi(16); b= [1 2 3 a];
These will eliminate answers like #6.

frank mcnally on 15 Aug 2019

Tests allow incorrect solution to pass:

function y = existsInVector(a,b)
y=0
for i = 1:numel(b);
if i==a
y=1
break
end
end
end

Jyothsna Chintala on 21 Apr 2020

good

Nicholas Bitler on 26 Nov 2020

that was fun, took me a couple minutes

Qingyin Zhang on 29 Nov 2020

y = sum(b == a);

Colin McNicholas on 13 Dec 2021

Not too bad

Hung Van Le on 24 Feb 2022

yay

Solution Comments

Solution 6810920

1 Comment

1 Comment

Josh Klueber on 2 Nov 2021

good problem

Solution 5669410

1 Comment

1 Comment

john perkins on 4 May 2021

this took me while good problem!

Solution 4748072

2 Comments

2 Comments

Michael Green on 4 Feb 2021

One line :)

Isabella Stellitano on 3 Nov 2021

GOOD

Solution 4143245

1 Comment

1 Comment

Cory Cunningham on 11 Dec 2020

I finally got it!

Solution 3602815

2 Comments

2 Comments

Swati Sarangi on 10 Nov 2020

Can anyone tell me what's wrong in this code as I am getting the desired result in my laptop?

function y = existsInVector(a,b)
for i=1:length(b)
if a==b(i)
y=1
elseif
i=i+1
if i==3
y=0
end
end
end
end

arsenic 陈 on 11 Mar 2021

u have finished just theexample
function y = existsInVector(a,b)
y=1-isempty(find(a==b));
end

Solution 3277703

1 Comment

1 Comment

Joseph Martel-Foley on 19 Oct 2020

Add a test for multiple matches in the vector.

Solution 3205066

Solution 3064189

Solution 2905837

1 Comment

1 Comment

Peter Jan Struiving on 31 Mar 2021

Leading solutions are still broken

Solution 2586241

1 Comment

1 Comment

Piero Cimule on 19 Jun 2020

if true(find(b == a))
y = 1
else
y = 0
end

Solution 1936828

Solution 1173654

1 Comment

1 Comment

Ernest Woei on 27 Apr 2017

While evaluating the solution, the server encountered an error caused by temporary unavailability of MATLAB Service. Wait a few minutes for the MATLAB Service to return, and then rescore.

function y = existsInVector(a,b)
y=ismember(a,b);
end

Solution 899430

1 Comment

1 Comment

Joe Smith on 31 May 2016

There is a pre-made function for this.
y = ismember(a,b)

Solution 113925

1 Comment

1 Comment

Nichlas on 17 Jul 2012

Thanks! Have updated tests.

Problem Recent Solvers7262

Problem Tags

basic matlab vectors

Community Treasure Hunt

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

Start Hunting!