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소식봇 2023. 6. 21. 12:01

^(11+?)\1+$/ that can be used to check if a number is prime. The regular expression works by generating a string of 1s based on the number and checking if that string matches the pattern. The pattern matches either 1 or an empty string, or a string with repeating blocks of 11 or more 1s. If the string of 1s for a number does not match the pattern, then the number is prime. The author provides examples showing how the regular expression works for numbers like 7, 9 and 13. The author finds the regular expression to be both easy to understand and beautiful.

원문: https://www.noulakaz.net/2007/03/18/a-regular-expression-to-check-for-prime-numbers/


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