Problem 2040. Additive persistence

• Created by Jean-Marie Sainthillier
• Appears in 2 groups

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Magic Numbers

• 19 Problems
• 84 Finishers

Number theory

• 44 Problems
• 21 Finishers

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Inspired by Problem 2008 created by Ziko.

In mathematics, the persistence of a number is the number of times one must apply a given operation to an integer before reaching a fixed point; where further application does not change the number any more (Wikipedia).

Problem 2008 is an example of multiplicative persistence. Can you code an additive persistence ?

2718->2+7+1+8=18->1+8=9. So the persistence of 2718 is 2.

You can use the tips : num2str(666)-'0'=[6 6 6].

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Solution Stats

57.05% Correct | 42.95% Incorrect

• 319 Solutions
• 172 Solvers

Last Solution submitted on Feb 26, 2025

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