-
Notifications
You must be signed in to change notification settings - Fork 0
/
p47.py
56 lines (47 loc) · 1.07 KB
/
p47.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
# -*- coding: utf-8 -*-
"""
Created on Tue Mar 21 11:22:11 2017
@author: Refaia
"""
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 primeFactors(n):
i = 2
factors = set()
if isPrime(n) :
factors.add(n)
else :
while i * i <= n:
if n % i != 0:
i += 1
else:
n //= i
factors.add(i)
if n > 1:
factors.add(n)
return len(factors)
def main() :
delta = time.time()
firstPrime = 0
pos = 2
length = 4
while True:
if primeFactors(pos) == length and primeFactors(pos + 1) == length and primeFactors(pos + 2) == length and primeFactors(pos + 3) == length :
firstPrime = pos
break
pos += 1
delta = time.time() - delta
return firstPrime, delta
print(main())