def trucate(n):
if not isprime(n):
return False
_strn = str(n)
for i in range(len(_strn) - 1):
if not(isprime(int(_strn[0:-1 - i])) and isprime(int(_strn[i + 1:]))):
return False
return True
def problem41():
_prm = [i for i in range(3, 50, 2) if isprime(i)]
_flg = False
for i in range(7654321, 1234567, -2):
if not ispandigital(i, 8):
continue
if (isprime(i)):
print("PRIME:", i)
break;
def problem10():
_sum = 2
for i in range(3, 2 * 1000 * 1000, 2):
if isprime(i):
_sum += i
# print(i)
print(_sum)
def problem7(): # a bit slow, but correct
count = 2
i = 3
while count != 10001:
i += 2
if isprime(i):
count += 1
print("count: {0}, i:{1}.".format(count, i))
def problem35():
_n = 1000 * 1000
_count = 0
for i in range(_n):
is_rotations_prime = True
for j in rotations(i):
if not isprime(j):
is_rotations_prime = False
break;
if (is_rotations_prime == True):
_count += 1
print(_count)
def problem3(): # correct
n = 600851475143
for i in range(int(n**0.5), 2, -1):
if (n % i == 0) and (isprime(i)):
print("that's {0}.".format(i))
break
