Python/maths/prime_sieve_eratosthenes.py
Andrey 584e743422
Fix yesqa hook (#7843)
* fix yesqa hook

* Remove redundant noqa

* updating DIRECTORY.md

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
2022-10-29 15:07:02 +02:00

46 lines
821 B
Python

"""
Sieve of Eratosthenes
Input : n =10
Output: 2 3 5 7
Input : n = 20
Output: 2 3 5 7 11 13 17 19
you can read in detail about this at
https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
"""
def prime_sieve_eratosthenes(num):
"""
print the prime numbers up to n
>>> prime_sieve_eratosthenes(10)
2,3,5,7,
>>> prime_sieve_eratosthenes(20)
2,3,5,7,11,13,17,19,
"""
primes = [True for i in range(num + 1)]
p = 2
while p * p <= num:
if primes[p]:
for i in range(p * p, num + 1, p):
primes[i] = False
p += 1
for prime in range(2, num + 1):
if primes[prime]:
print(prime, end=",")
if __name__ == "__main__":
import doctest
doctest.testmod()
num = int(input())
prime_sieve_eratosthenes(num)