def solution():
# n = 2143
# n_max = 987654321
# for x in range(n, n_max+1, 2):
# if is_prime(x):
# if check_one_to_n(x):
# if is_pandigital(x):
# print(x, 'is pandigital prime')
# break
# x = 987654321
# while True:
# # print('checking', x)
# if check_one_to_n(x):
# print(x, 'is made of 1-n digits, each digit exactly once')
# if is_prime(x):
# print(x, 'is prime')
# if is_pandigital(x):
# print(x, 'is pandigital prime')
# break
# x -= 2
max_panprime = 2143
for n in range(9, 1, -1):
permutes = permute_n_digits(n)
nums = [digitlist_to_num(p) for p in permutes]
for num in nums:
if check_one_to_n(num):
if is_prime(num) and is_pandigital(num):
if num > max_panprime:
max_panprime = num
if max_panprime > 2143:
break
return max_panprime
def solution():
permutes = permute_n_digits(9, nfirst=0)
nums = [digitlist_to_num(p) for p in permutes]
# filter out those starting with 0
nums = [num for num in nums if len(str(num))==10]
ans = 0
for num in nums:
if check_substring_divis(num):
ans += num
return ans
def check_truncatable(num):
len_num = len(str(num))
if (len_num < 2) or (not is_prime(num)):
return False
digitlist = num_to_digitlist(num)
trun_left = []
trun_right = []
for i in range(1, len_num):
trun_left.append(digitlist_to_num(digitlist[i:]))
trun_right.append(digitlist_to_num(digitlist[:-i]))
all_truns = set(trun_left + trun_right)
print('all truns:', all_truns)
for n in all_truns:
if not is_prime(n):
return False
return True
def solution(n_fam, verbose=False):
len_n = 2
while True:
n_min, n_max = get_min_max(len_n)
possible_n_replaces = range(1, len_n)
# print(n_min, n_max)
primes = []
for n in range(n_min+1, n_max+1):
if is_prime(n):
primes.append(n)
if len(primes) == 0:
len_n += 1
continue
for p in primes:
# p_digitlist = num_to_digitlist(p)
for nr in possible_n_replaces:
poss_nr_idxs = list(combinations(range(len_n), nr))
for nr_idxs in poss_nr_idxs:
if verbose:
print('index/indices to replace:', nr_idxs)
if 0 in nr_idxs:
r_digits = range(1, 10)
else:
r_digits = range(0, 10)
prime_family = []
for r in r_digits:
p_replist = num_to_digitlist(p)
for nr_idx in nr_idxs:
# print(nr_idx, r)
p_replist[nr_idx] = r
p_rep_num = digitlist_to_num(p_replist)
if is_prime(p_rep_num):
prime_family.append(p_rep_num)
if verbose:
print(p, prime_family)
if len(prime_family) == n_fam:
# print(prime_family)
return min(prime_family)
len_n += 1
def convert_base(num_base10, base_to):
# find max_pow
imax = 0
while base_to ** imax <= num_base10:
# print(base_to ** imax, num_base10)
imax += 1
imax -= 1
# print('max power in base {}: {}'.format(base_to, imax))
new_digitlist = []
for i in range(imax, -1, -1):
# print('finding power', imax)
digit = num_base10 // (base_to ** i)
if digit != 0:
num_base10 = num_base10 - (digit) * (base_to ** i)
new_digitlist.append(digit)
new_num = digitlist_to_num(new_digitlist)
return new_num
def permutes_of_num(num):
digitlist = num_to_digitlist(num)
permutes = list(permutations(digitlist))
permute_nums = [digitlist_to_num(p) for p in permutes]
return permute_nums