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p46.py
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p46.py
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# -*- coding: utf-8 -*-
"""
Created on Fri Mar 17 10:08:25 2017
@author: Refaia
"""
import math
import time
def isPrime(n) :
if n <= 1 :
return False
if n <= 3 :
return True
if n % 2 == 0 or n % 3 == 0 :
return False
i = 5
while i * i <= n :
if n % i == 0 or n % (i + 2) == 0 :
return False
i += 6
return True
def main() :
num = 35
delta = time.time()
result = 0
while True :
if isPrime(num) :
num += 2
continue
canBeWritten = False
for prime in range(3, num, 2):
if isPrime(prime) :
if (num - prime) % 2 == 0 :
if int(math.sqrt((num - prime) / 2)) == math.sqrt((num - prime) / 2) :
canBeWritten = True
break
if not canBeWritten :
result = num
break
num += 2
delta = time.time() - delta
return result , delta
'''
def primeBelow(n):
if n < 2:
return 0
if n == 2 :
return [2]
primeList = []
listNum = [2] + [i for i in range(3, n + 1, 2)]
for i in range(1, int(math.sqrt(n)) + 1, 1):
if listNum[i] :
for j in range(i + listNum[i], len(listNum), listNum[i]):
listNum[j] = 0
for num in listNum :
if num :
primeList.append(num)
return primeList
def main() :
num = 35
delta = time.time()
result = 0
while True and num < 10000:
L = primeBelow(num)
if num in L :
num += 2
continue
canBeWritten = False
for prime in L:
if (num - prime) % 2 == 0 :
if int(math.sqrt((num - prime) / 2)) == math.sqrt((num - prime) / 2) :
canBeWritten = True
break
if not canBeWritten :
result = num
break
num += 2
delta = time.time() - delta
return result , delta
'''
print(main())