Problem 234. Project Euler: Problem 3, Largest prime factor

Created by Doug Hull

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>The prime factors of 13195 are 5, 7, 13 and 29.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>What is the largest prime factor of the number being input, input might be uint64 for large numbers, out must be double precision?</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Thank you to</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"http://projecteuler.net/problem=3\"><w:r><w:t>Project Euler Problem 3</w:t></w:r></w:hyperlink></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

3560 Solutions
1038 Solvers

Last Solution submitted on Mar 24, 2023

Last 200 Solutions

Problem Comments

1 Comment

1 Comment

Mahaveer Singh on 23 May 2021

good level

Solution Comments

Solution 4576068

1 Comment

1 Comment

Lingjun Ding on 11 Jan 2021

not good, doesn't work for prime numbers
My idea was like Solution 1669655, that one is much better

Solution 3884758

1 Comment

1 Comment

Adam Turner on 28 Nov 2020

The last test is not appropriate. 13916767508299776 exceeds flintmax, eg. 9.007199254740992e+15. It causes precision problem when it is passed to euler003.

Solution 3054286

1 Comment

1 Comment

Abhijeet Deshmukh on 4 Oct 2020

I am failing to pass the last test of this code ,I am using max and factor ,any hint to pass last , 7th number test?

Solution 1632904

1 Comment

1 Comment

Jitesh Kumar on 25 Sep 2018

why it is not accepting the answer ;we cant make such small solutions we are not like professional coder

Solution 26559

2 Comments

2 Comments

Alfonso Nieto-Castanon on 3 Feb 2012

still something fishy with the 3rd problem, example:
x = uint64(321676750829977632);
num2str(x) -> 321676750829977600
rem(x,10) -> 0
euler003(x) -> 83653987
...?

Alfonso Nieto-Castanon on 3 Feb 2012

ok now, it seems this was only an issue with my matlab version (7.7) but was not present in the version running the solvers (which seems to have uint64 arithmetic supported!, man, I need an upgrade...)

Solution 25119

3 Comments

3 Comments

Tomasz on 2 Feb 2012

You should pass the x values as a string. A double precision number cannot resolve all the digits that one needs to solve the test suite problems:

>> x = 321676750829977632;
>> x == x+1
ans =
1

@bmtran (Bryant Tran) on 2 Feb 2012

I agree that there is an issue with the last test suite problem. passing it as a uint64 would work too.

Franck Dernoncourt on 2 Feb 2012

Yep I got "Error: Out of memory. Type HELP MEMORY for your options." :-)

Problem Recent Solvers1038

Problem Tags

Community Treasure Hunt

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

Start Hunting!

Problem 234. Project Euler: Problem 3, Largest prime factor

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers1038

Suggested Problems

More from this Author51

Problem Tags

Community Treasure Hunt

Problem 234. Project Euler: Problem 3, Largest prime factor

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers1038

Suggested Problems

More from this Author51

Problem Tags

Community Treasure Hunt

Players