Problem 813. Multiply 2 numbers

Created by Aurelien Queffurust

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>Very easy, you just have to multiply 2 numbers but you cannot use the following signs (*, /, - ,^) ,mtimes , times, cross, prod, cumprod , dec2bin, int2str and num2str functions. Will you take up the challenge?!</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>Example : x= 3; y= 2;</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>output = 6 since 3*2 = 6 :)</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

2152 Solutions
264 Solvers

Last Solution submitted on Nov 28, 2020

Last 200 Solutions

Problem Comments

4 Comments

4 Comments

Show 1 older comment

Aurelien Queffurust on 9 Jul 2012

As Richard made me notice by email, tests 5 and 6 (using randi and non-integer) were not enable. As I have rescored all solutions, some previous solutions which passed the test, do not pass it anymore.

James on 9 Jul 2012

Can you please set a tolerance for the submitted answers? Using exp(log(x)+log(y)) fails nearly all possibilities for test case 5, with the biggest error being roughly 2.5e-11.

Ilias Patelakis on 24 Oct 2017

Nice one. It would be more challenging to add a test case where both function arguments are decimal numbers. :)

Jiahang Li on 4 Feb 2018

You can try adding, and something wonderful happens.

Solution Comments

Solution 1445729

1 Comment

1 Comment

md.wahid tousif_rahman on 21 Feb 2018

Most foul one

Solution 1433565

1 Comment

1 Comment

Jiahang Li on 4 Feb 2018

funny~

Solution 1117273

1 Comment

1 Comment

Jess Stuart on 8 Feb 2017

exp(log(x)+log(y)) works with a trivial amount of roundoff error. Matlab is a numeric language. Using Isequal() is dumb.

Solution 415606

2 Comments

2 Comments

Dimitrios on 8 Mar 2014

i cant understand why test 1 fails :/

Aurelien Queffurust on 10 Mar 2014

It fails because you use the minus sign and there is the following test :
assert(isempty(strfind(filetext, '-')))

Solution 362049

2 Comments

2 Comments

Ramoflaple on 11 Aug 2015

good use of 'linspace'

David Verrelli on 10 Nov 2017

What if _both_ x _and_ y were either negative or non-integers though?

Solution 250534

2 Comments

2 Comments

Kumar on 29 May 2013

Test 1 is always showing Fail. This is disgusting. May be some error on the creator part. Kindly check...

Ned Gulley on 29 May 2013

The error for Test 1 says "Output argument 'output' (and maybe others) not assigned". Close examination of your code reveals that when x is 1 and y is 2, you go down the first switch of the outer "if" statement, and sure enough, output never gets assigned and the function fails.

Solution 106284

1 Comment

1 Comment

David Young on 4 Jul 2012

Only works for scalars of course.

Problem Recent Solvers264

Problem Tags

multiplication product

Community Treasure Hunt

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

Start Hunting!

Problem 813. Multiply 2 numbers

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers264

Suggested Problems

More from this Author30

Problem Tags

Community Treasure Hunt

Problem 813. Multiply 2 numbers

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers264

Suggested Problems

More from this Author30

Problem Tags

Community Treasure Hunt

Players