import prime
prime_list = prime.myprime(1000000)
prime_dict = {}
for ps in prime_list:
prime_dict[ps] = 1
def isprime(n):
if prime_dict.has_key(n):
return True
for ps in prime_list:
if ps * ps > n: return True
if n % ps == 0: return False
return True
side = 3
total_diag = 5
p = [3, 5, 7]
ratio = len(p) * 1.0 / total_diag
while ratio > 0.1:
side = side + 2
total_diag += 4
p1 = side * side - side + 1
if isprime(p1): p.append(p1)
p1 = p1 - side + 1
if isprime(p1): p.append(p1)
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: Junjie Bian
# File Name: pro21.py
# Description:
import prime
from datetime import datetime
print datetime.now()
p = prime.myprime(30000)
def explode(num):
d = {}
global p
i = 0
while num != 1:
if num % p[i] == 0:
num /= p[i]
d[p[i]] = d.get(p[i], 0) + 1
else:
i += 1
return d
MAX_NUM = 28123
def sumup(num):
if len(numStr) == 1:
return [numStr]
l = list(numStr)
P = []
for i in l:
T = copy(l)
T.remove(i)
newNumStr = ''.join(T)
rs = permutation(newNumStr)
for r in rs:
P.append(i + r)
return P
plist = myprime(10000)
pdict = {}
for p in plist:
pdict[p] = 1
for p in plist:
if p < 1000:
continue
if not pdict.has_key(p):
continue
ps = permutation(str(p))
ps = [int(pp) for pp in ps]
ps = list(set(ps))
ps = [i for i in ps if pdict.has_key(i) and i > 1000]
# print ps
import prime
primes = prime.myprime(10000)
primes_dict = {}
for p in primes:
primes_dict[p] = 1
def isPrime(n):
if primes_dict.has_key(n): return True
for p in primes:
if p * p > n: return True
if n % p == 0: return False
return True
def concate(m, n):
return m * (10**len(str(n))) + n
def isPair(m, n):
return isPrime(concate(m, n)) and isPrime(concate(n, m))
def filter_bad(ps):
index = [0] * len(ps)
for i in range(len(ps)):
print i
for j in range(i + 1, len(ps)):
if isPair(ps[i], ps[j]):
import prime
prime_list = prime.myprime(1000000)
prime_dict = {}
for val in prime_list:
prime_dict[val] = True
def expand_to_primes(n):
d = {}
i = 0
while i<len(prime_list):
if n% prime_list[i]==0:
d[prime_list[i]] = d.get(prime_list[i],0)+1
n /= prime_list[i]
else:
i=i+1
if n==1: break
return d
best_n = -1
best_ans=-1
N = 1000000+1
ans_dict={}
for val in prime_list:
ans_dict[val] = val -1
for val in prime_list:
cur = val*val
k = 2
while cur<N:
import prime
primes = prime.myprime(10000)
primes_dict = {}
for p in primes:
primes_dict[p] = 1
def isPrime(n):
if primes_dict.has_key(n): return True
for p in primes:
if p*p>n: return True
if n%p==0: return False;
return True
def concate(m,n):
return m*(10**len(str(n)))+n
def isPair(m,n):
return isPrime(concate(m,n)) and isPrime(concate(n,m))
def filter_bad(ps):
index = [0] * len(ps)
for i in range(len(ps)):
print i
for j in range(i+1, len(ps)):
if isPair(ps[i], ps[j]):
index[i] += 1
print ps[j],
print
print index
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: Junjie Bian
# File Name: pro21.py
# Description:
import prime
from datetime import datetime
print datetime.now()
p=prime.myprime(30000)
def explode(num):
d={}
global p
i=0
while num!=1:
if num % p[i]==0:
num/=p[i]
d[p[i]]=d.get(p[i],0)+1
else:
i+=1
return d
MAX_NUM=28123
def sumup(num):
d=explode(num)
s=1
for k in d.keys():
s=s*(1- k**(d[k]+1))/(1-k)
if len(numStr) == 1:
return [numStr]
l = list(numStr)
P = []
for i in l:
T = copy(l)
T.remove(i)
newNumStr = "".join(T)
rs = permutation(newNumStr)
for r in rs:
P.append(i + r)
return P
plist = myprime(10000)
pdict = {}
for p in plist:
pdict[p] = 1
for p in plist:
if p < 1000:
continue
if not pdict.has_key(p):
continue
ps = permutation(str(p))
ps = [int(pp) for pp in ps]
ps = list(set(ps))
ps = [i for i in ps if pdict.has_key(i) and i > 1000]
# print ps
if (num == 2 or num == 3 or num == 5):
return True
if (num % 2 == 0 or num % 3 == 0 or num % 5 == 0):
return False
sq = int(math.sqrt(num))
i = 3
while i <= sq:
if num % i == 0:
return False
i += 2
return True
pb = prime.myprime(1000)
def myfunc(a, b, x):
return x * x + a * x + b
def quad(a, b):
n = 0
s = 0
while True:
if not isPrime(myfunc(a, b, n)):
break
n += 1
s += 1
return s
import prime
N = int(1e7)
prime_list = prime.myprime(N)
prime_dict = {}
for val in prime_list:
prime_dict[val] = True
def expand_to_primes(n):
d = {}
i = 0
while i < len(prime_list):
if n % prime_list[i] == 0:
d[prime_list[i]] = d.get(prime_list[i], 0) + 1
n /= prime_list[i]
else:
i = i + 1
if n == 1: break
return d
def is_permu(m, n):
m_str = ''.join(sorted(str(m)))
n_str = ''.join(sorted(str(n)))
if m_str == n_str: return True
return False
best_n = -1
best_ans = -1
if num == 2 or num == 3 or num == 5:
return True
if num % 2 == 0 or num % 3 == 0 or num % 5 == 0:
return False
sq = int(math.sqrt(num))
i = 3
while i <= sq:
if num % i == 0:
return False
i += 2
return True
pb = prime.myprime(1000)
def myfunc(a, b, x):
return x * x + a * x + b
def quad(a, b):
n = 0
s = 0
while True:
if not isPrime(myfunc(a, b, n)):
break
n += 1
s += 1
return s
import prime
N = int(1e7)
prime_list = prime.myprime(N)
prime_dict = {}
for val in prime_list:
prime_dict[val] = True
def expand_to_primes(n):
d = {}
i = 0
while i<len(prime_list):
if n% prime_list[i]==0:
d[prime_list[i]] = d.get(prime_list[i],0)+1
n /= prime_list[i]
else:
i=i+1
if n==1: break
return d
def is_permu(m, n):
m_str = ''.join(sorted(str(m)))
n_str = ''.join(sorted(str(n)))
if m_str == n_str: return True
return False
best_n = -1
best_ans=-1
ans_dict={}