Change prime_sieve_eratosthenes.py to return list (#8062)

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Tianyi Zheng 2023-01-01 17:10:59 -08:00 committed by GitHub
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@ -12,34 +12,43 @@ https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
"""
def prime_sieve_eratosthenes(num):
def prime_sieve_eratosthenes(num: int) -> list[int]:
"""
print the prime numbers up to n
Print the prime numbers up to n
>>> prime_sieve_eratosthenes(10)
2,3,5,7,
[2, 3, 5, 7]
>>> prime_sieve_eratosthenes(20)
2,3,5,7,11,13,17,19,
[2, 3, 5, 7, 11, 13, 17, 19]
>>> prime_sieve_eratosthenes(2)
[2]
>>> prime_sieve_eratosthenes(1)
[]
>>> prime_sieve_eratosthenes(-1)
Traceback (most recent call last):
...
ValueError: Input must be a positive integer
"""
primes = [True for i in range(num + 1)]
p = 2
if num <= 0:
raise ValueError("Input must be a positive integer")
primes = [True] * (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=",")
return [prime for prime in range(2, num + 1) if primes[prime]]
if __name__ == "__main__":
import doctest
doctest.testmod()
num = int(input())
prime_sieve_eratosthenes(num)
user_num = int(input("Enter a positive integer: ").strip())
print(prime_sieve_eratosthenes(user_num))