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45 lines
1.2 KiB
Python
45 lines
1.2 KiB
Python
'''Python program to print all Primes Smaller than or equal to N using Sieve of Eratosthenes'''
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import time
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import math
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def sieve_of_eratosthenes(num: int) -> list[int]:
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"""Finds all prime number from 1 to num.
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Args:
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num (int): Number up to which the prime numbers should be printed
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Returns:
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list[int]: List of prime numbers
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"""
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# boolean list
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prime = [True] * (num+1)
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p = 2
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while p <= math.sqrt(num):
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# If prime[p] is not
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# changed, then it is a prime
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if prime[p]:
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i = (p << 1)
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# Updating all multiples of p
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while i <= num:
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prime[i] = False
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i += p
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p += 1
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return [p for p in range(2, num+1) if prime[p]]
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def print_sieve(num: int) -> None:
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"""Prints all prime number from 1 to num.
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Args:
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num (int): Number up to which the prime numbers should be printed
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"""
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for number in sieve_of_eratosthenes(num):
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print(number, end=" ")
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# Driver code
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if __name__ == '__main__':
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num = 3000
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print("Following are the prime numbers smaller"),
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print("than or equal to", num)
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print_sieve(num) |