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"""Segmented Sieve."""
importmath
defsieve(n: int) ->list[int]:
"""
Segmented Sieve.
Examples:
>>> sieve(8)
[2, 3, 5, 7]
>>> sieve(27)
[2, 3, 5, 7, 11, 13, 17, 19, 23]
>>> sieve(0)
Traceback (most recent call last):
...
ValueError: Number 0 must instead be a positive integer
>>> sieve(-1)
Traceback (most recent call last):
...
ValueError: Number -1 must instead be a positive integer
>>> sieve(22.2)
Traceback (most recent call last):
...
ValueError: Number 22.2 must instead be a positive integer
"""
ifn<=0orisinstance(n, float):
msg=f"Number {n} must instead be a positive integer"
raiseValueError(msg)
in_prime= []
start=2
end=int(math.sqrt(n)) # Size of every segment
temp= [True] * (end+1)
prime= []
whilestart<=end:
iftemp[start] isTrue:
in_prime.append(start)
foriinrange(start*start, end+1, start):
temp[i] =False
start+=1
prime+=in_prime
low=end+1
high=min(2*end, n)
whilelow<=n:
temp= [True] * (high-low+1)
foreachinin_prime:
t=math.floor(low/each) *each
ift<low:
t+=each
forjinrange(t, high+1, each):
temp[j-low] =False
forjinrange(len(temp)):
iftemp[j] isTrue:
prime.append(j+low)
low=high+1
high=min(high+end, n)
returnprime
if__name__=="__main__":
importdoctest
doctest.testmod()
print(f"{sieve(10**6) =}")