Problem 44384. Find the nearest prime number

Created by Matthew Eicholtz

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Happy 5th birthday, Cody! Since 5 is a prime number, let's have some fun looking for other prime numbers.

Given a positive integer x, find the nearest prime number. Keep in mind that the nearest prime may be less than x.

Examples

nearestprime(5) = 5
nearestprime(36) = 37
nearestprime(200) = 199

NOTE: You may ignore cases in which two prime numbers are equally close to x. (e.g., x=12 --> 11 and 13 are both primes).

Solve

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1779 Solutions
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Last Solution submitted on Nov 21, 2019

Last 200 Solutions

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Tran Hiep Dinh on 21 Mar 2019

Test case No. 5
x = 911;
y_correct = 911;

Should the nearest prime number for 911 have been 907?

Solution Comments

Solution 1397315

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Francis Naldo on 29 Dec 2017

Look. It's Size 80

Solution 1317338

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1 Comment

Igor Gaponov on 21 Dec 2017

I feel for you, typing in those endless arrays of prime numbers.
You have probably figured it out by now, but instead of typing in manually the vectors prim0 and prim1 and then checking memberships, you can just run the function 'isprime(x)' which will save you lots of space and time

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cody5 prime numbers

Problem 44384. Find the nearest prime number

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Last 200 Solutions

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Problem 44384. Find the nearest prime number

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Last 200 Solutions

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Problem Recent Solvers461

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