Rebased projecteuler folder, now includes all contest programming stuff
This commit is contained in:
49
projecteuler/041/main.py
Normal file
49
projecteuler/041/main.py
Normal file
@@ -0,0 +1,49 @@
|
||||
'''
|
||||
We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once. For example, 2143 is a 4-digit pandigital and is also prime.
|
||||
|
||||
What is the largest n-digit pandigital prime that exists?
|
||||
'''
|
||||
|
||||
import math
|
||||
import numpy as np
|
||||
|
||||
def sieve(n):
|
||||
assert n > 1
|
||||
|
||||
ns = [True] * n
|
||||
|
||||
for i in range(2, math.ceil(np.sqrt(n))):
|
||||
if ns[i]:
|
||||
j = pow(i, 2)
|
||||
|
||||
while j < n:
|
||||
ns[j] = False
|
||||
j = j + i
|
||||
|
||||
return [i for i,val in enumerate(ns) if val][2:]
|
||||
|
||||
def isPandigital(n):
|
||||
l = len(str(n))
|
||||
|
||||
digits = set(range(1, l+1))
|
||||
|
||||
if digits == set(map(int, str(n))):
|
||||
return True
|
||||
return False
|
||||
|
||||
def main():
|
||||
print("Hello this is Patrick")
|
||||
|
||||
primes = sieve(987654321)
|
||||
|
||||
print("Calculated enough primes")
|
||||
|
||||
r = 1
|
||||
|
||||
while not isPandigital(primes[-1 * r]):
|
||||
r += 1
|
||||
|
||||
print(primes[-1 * r])
|
||||
|
||||
if __name__ == "__main__":
|
||||
main()
|
||||
Reference in New Issue
Block a user