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Solution to problem 60 in Python

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David Doblas Jiménez 2021-12-04 17:39:28 +01:00
parent 037f4c0f8d
commit 6157818ad0
1 changed files with 21 additions and 11 deletions
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src/Python/Problem060.py
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@ -1,6 +1,6 @@
#!/usr/bin/env python3 #!/usr/bin/env python3
""" """
Created on 13 Oct 2021 Created on 04 Dic 2021
@author: David Doblas Jiménez @author: David Doblas Jiménez
@email: daviddoji@pm.me @email: daviddoji@pm.me
@ -9,8 +9,7 @@ Solution for problem 60 of Project Euler
https://projecteuler.net/problem=60 https://projecteuler.net/problem=60
""" """
from itertools import permutations from utils import timeit, list_primes, is_prime
from utils import timeit, list_primes
@timeit("Problem 60") @timeit("Problem 60")
@ -28,15 +27,26 @@ def compute():
primes_list = list_primes(10_000) primes_list = list_primes(10_000)
for nums in permutations(primes_list, 5): def solve_backtrack(max_chain_length, chain):
for n1, n2 in permutations(nums, 2): for p in primes_list[1:]:
if int(str(n1) + str(n2)) not in primes_list: if p not in chain and is_concatenable(chain, p):
break chain.append(p)
primes = sum(nums) if len(chain) == max_chain_length:
print(nums) return chain
# break solve_backtrack(max_chain_length, chain)
chain.pop()
return chain
return primes def is_concatenable(chain, candidate):
for n in chain:
if not is_prime(int(str(n) + str(candidate))):
return False
if not is_prime(int(str(candidate) + str(n))):
return False
return True
result = solve_backtrack(5, [])
return sum(result)
if __name__ == "__main__": if __name__ == "__main__":