46 lines
1.1 KiB
Python
46 lines
1.1 KiB
Python
from itertools import combinations, permutations
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from lib_prime import is_prime_rabin_miller as is_prime
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def as_number(xs) -> int:
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return int("".join(map(str, xs)))
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def list_diff(xs, ys):
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xs = list(xs)
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for y in ys:
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xs.remove(y)
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return xs
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def combs(xs, size):
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return sorted([p
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for cs in combinations(xs, size)
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for p in permutations(cs)])
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def count(min_set_size: int, min_num: int, remaining: list[int]) -> int:
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if not remaining:
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return 1
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result = 0
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# There are no pandigital primes with 9 digits, so we only check till 8.
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for set_size in range(min_set_size, 9):
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for subset in combs(remaining, set_size):
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n = as_number(subset)
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if n > min_num and is_prime(n):
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new_remaining = list_diff(remaining, subset)
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result += count(set_size, n, new_remaining)
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return result
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def euler_118():
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return count(1, 0, [1, 2, 3, 4, 5, 6, 7, 8, 9])
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if __name__ == "__main__":
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solution = euler_118()
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print("e118.py: " + str(solution))
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assert(solution == 44680)
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