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- Project Euler #248: Numbers for which Euler’s totient function equals 13!
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# Project Euler #248: Numbers for which Euler’s totient function equals 13!

# Project Euler #248: Numbers for which Euler’s totient function equals 13!

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Just pass the first test, any example to test against it that I can use? how do I know where I'm failing

from math import factorial

def gcd(p,q): while q != 0: p, q = q, p%q return p def is_coprime(x, y): return gcd(x, y) == 1

c=list(map(int,input().rstrip().split())) d=[] n= factorial(c[0]) b= 1 for i in range(n-1,2,-1): if (is_coprime(n,i)==1): b+=1 break d.append(i)

print(d[len(d)-1])

this code is working for smaller values but with the inputs of the problem it is showing time out please help

My program finds 13!'s divisors 66528 and 93600 (among others) because their successor is a prime and combines them. Sorting those roughly 180000 numbers finishes almost instantly but I went the crazy way and preferred ''std::nth_element'' because it is a little bit more efficient - but you can't measure the performance advantage

To check the cardinality ("checksum") of your sets ϕ

^{-1}(m), consider these resources I used:^{12}is our Python's limit_{o}of odd members of ϕ^{-1}(2^{k}) is 1 if 0 ≤ k < 32 and 0 for k ≥ 32. Furthermore, that paper includes an explicit list for m=576, as well as a useful table of even-odd checksums for ϕ^{-1}([1,...,m]).In Python testcases, the limit for time is 20 seconds and memory is 512 megabytes. My

Python3code runs under 360 milliseconds; its own prime factorization uses memo-ization.can anyone explain the question?