Problem 49778. Determine whether a number is a prime self number

Created by ChrisR

Solve Later

{"parts":[{"partUri":"/matlab/document.xml","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:jc w:val=\"left\"/></w:pPr><w:r><w:t>Integers can be classified as </w:t></w:r><w:r><w:rPr><w:i/></w:rPr><w:t>generated</w:t></w:r><w:r><w:t> numbers or </w:t></w:r><w:r><w:rPr><w:i/></w:rPr><w:t>self </w:t></w:r><w:r><w:t>numbers. A generated number is one that can be expressed as the sum of another number and its digit sum. For example, 15 can be written as 12+(1+2); in other words, 15’s generator is 12. A self number cannot be expressed in this way. </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>Write a function to determine whether a number is a </w:t></w:r><w:r><w:rPr><w:i/></w:rPr><w:t>prime</w:t></w:r><w:r><w:t> self number. </w:t></w:r></w:p></w:body></w:document>","relationship":null}],"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","target":"/matlab/document.xml","relationshipId":"rId1"}]}

<div style = "text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; "><div style="block-size: 93px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 46.5px; transform-origin: 407px 46.5px; vertical-align: baseline; "><div style="block-size: 63px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 31.5px; text-align: left; transform-origin: 384px 31.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; "><span style="block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 90.2417px 8.05px; transform-origin: 90.2417px 8.05px; unicode-bidi: normal; "><span style="">Integers can be classified as </span></span><span style="block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 31.5167px 8.05px; transform-origin: 31.5167px 8.05px; unicode-bidi: normal; "><span style="font-style: italic; ">generated</span></span><span style="block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 39.2833px 8.05px; transform-origin: 39.2833px 8.05px; unicode-bidi: normal; "><span style=""> numbers or </span></span><span style="block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 12.8333px 8.05px; transform-origin: 12.8333px 8.05px; unicode-bidi: normal; "><span style="font-style: italic; ">self </span></span><span style="block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 209.267px 8.05px; transform-origin: 209.267px 8.05px; unicode-bidi: normal; "><span style="">numbers. A generated number is one that can be expressed as the sum of another number and its digit sum. For example, 15 can be written as 12+(1+2); in other words, 15’s generator is 12. A self number cannot be expressed in this way. </span></span></div><div style="block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; "><span style="block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 162.458px 8.05px; transform-origin: 162.458px 8.05px; unicode-bidi: normal; "><span style="">Write a function to determine whether a number is a </span></span><span style="block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 17.5083px 8.05px; transform-origin: 17.5083px 8.05px; unicode-bidi: normal; "><span style="font-style: italic; ">prime</span></span><span style="block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 42px 8.05px; transform-origin: 42px 8.05px; unicode-bidi: normal; "><span style=""> self number. </span></span></div></div></div>

Solve

Solution Stats

28 Solutions
11 Solvers

Last Solution submitted on Feb 05, 2022

Last 200 Solutions

Problem Comments

2 Comments

2 Comments

J.R.! Menzinger on 4 Aug 2021

Nice Problem!

but I found remarkable your syntax on test case Nr. 27:
a = arrayfun(@(k) isPrimeSelf(n(k)),1:length(n));

if you use 'arrayfun' you can actually parse the vector directly and you can avoid parsing the indices. The following expression would be more narrow:

a = arrayfun(@isPrimeSelf,n)

ChrisR on 28 Aug 2021

Thanks for pointing that out. I've made the change.

Problem Recent Solvers11

Problem Tags

Community Treasure Hunt

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

Start Hunting!

Problem 49778. Determine whether a number is a prime self number

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers11

Suggested Problems

More from this Author164

Problem Tags

Community Treasure Hunt

Problem 49778. Determine whether a number is a prime self number

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers11

Suggested Problems

More from this Author164

Problem Tags

Community Treasure Hunt

Players