Python/project_euler/problem_07/sol3.py
Christian Clauss 28419cf839 pyupgrade --py37-plus **/*.py ()
* pyupgrade --py37-plus **/*.py

* fixup! Format Python code with psf/black push
2020-01-03 22:25:36 +08:00

47 lines
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Python

"""
By listing the first six prime numbers:
2, 3, 5, 7, 11, and 13
We can see that the 6th prime is 13. What is the Nth prime number?
"""
import math
import itertools
def primeCheck(number):
if number % 2 == 0 and number > 2:
return False
return all(number % i for i in range(3, int(math.sqrt(number)) + 1, 2))
def prime_generator():
num = 2
while True:
if primeCheck(num):
yield num
num += 1
def solution(n):
"""Returns the n-th prime number.
>>> solution(6)
13
>>> solution(1)
2
>>> solution(3)
5
>>> solution(20)
71
>>> solution(50)
229
>>> solution(100)
541
"""
return next(itertools.islice(prime_generator(), n - 1, n))
if __name__ == "__main__":
print(solution(int(input().strip())))