Problem 1444. Dots in a Circle

Created by Yaroslav

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 how many integer grid points there are inside a circle of radius</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:i/></w:rPr><w:t>r</w:t></w:r><w:r><w:t> centred at (0,0) (including points on the edge).</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Neither</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:b/></w:rPr><w:t>string operations</w:t></w:r><w:r><w:t> nor</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:b/></w:rPr><w:t>interpolations</w:t></w:r><w:r><w:t> are allowed!</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

333 Solutions
87 Solvers

Last Solution submitted on May 22, 2022

Last 200 Solutions

Problem Comments

5 Comments

5 Comments

Show 2 older comments

Michael C. on 22 Apr 2013

I think there is an error with the r = 7.5 test case. By the definition of the problem, it should be 177, not 172. The working solutions use a mesh that is not on integer grid points.

James on 23 Apr 2013

I also got 177 for r=7.5 as well using (the cody unfriendly) two for loops.

Yaroslav on 23 Apr 2013

@Michael_C. and @James, Thank you! I have indeed overlooked that edge case. The problem is now fixed. (The "for" loops are unnecessary).

James on 23 Apr 2013

Yaroslav, you are certainly correct that for loops are not needed. I just used them to confirm that my answer using the "no-for-loop-required algorithm" was correct before commenting on the problem. My similar problem (Cody problem 1387) only used integer radii.

Claudio Gelmi on 24 Apr 2013

Thanks for the correction!

Problem Recent Solvers87

Problem Tags

geometry grid

Community Treasure Hunt

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

Start Hunting!

Problem 1444. Dots in a Circle

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers87

Suggested Problems

More from this Author18

Problem Tags

Community Treasure Hunt

Problem 1444. Dots in a Circle

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers87

Suggested Problems

More from this Author18

Problem Tags

Community Treasure Hunt

Players