Had some crazy problems using python..

Here's my java printouts

prime loaded

load size:5761455

prime loaded time: 2576ms

prime re loaded

re load size:335534

prime loaded time: 15204ms

sum = 1739023853137

Total execution time: 37109ms

And here's what i got running python

loaded primes: len = 5761455

49.328213691711426 s

loaded primes: len = 335534

582.0822110176086 s

0

100000

200000

300000

[1, 2, 6...]

1739023853137

1410.7866961956024 s

Guess python really don't fit into this problem..

1. generate all primes under 100,000,000 using sieve method

2. filter out primes, if 2+d/2 is not prime (d is already x-1 from sieve primes)

3. filter out primes if they are multiples of the 100 primes squared

4. now the primes will be added if they are generators for factors..

python code goes here, but it's really slow

Python

Hide Code

def sieveE(n):

'''

generate primes using sieve of eratosthenes method

:param n: prime up to n

:return: list containing all primes less than n

'''

A = [True] * (n + 1)

A[0] = A[1] = False

for i in range(2, int(math.sqrt(n) + 1)):

if A[i]:

j = i * i

while (j <= n):

A[j] = False

j += i

return [i for i in range(0, n + 1) if A[i]]

def factors(n):

for x in range(1,int(math.sqrt(n))+1):

if n%x==0:

if not isPrime(x + n/x):

return False

return True

s = time.time()

g =[]

x = sieveE(100000000)

print('loaded primes: len = %d' % len(x))

print(time.time()-s)

x[:] = [a-1 for a in x]

h = sieveE(100)

h[:] = [m*m for m in h]

A = [True]*len(x)

c = 0

for i in range(len(x)):

# all x are even

if not isPrime(2 + x[i]/2):

A[i] = False

for i in range(len(x)):

if A[i] and any(x[i] % f == 0 for f in h):

A[i] = False

xnew = []

for i in range(len(x)):

if A[i] == True:

xnew.append(x[i])

print('loaded primes: len = %d' % len(xnew))

print(time.time()-s)

c = 0

for i in range(len(xnew)):

if c % 1e5 == 0:

print(c)

if factors(xnew[i]):

g.append(xnew[i])

c += 1

print(g)

print(sum(g))

print(time.time()-s)