def buildPrimeList():
count=1
num=3
while True:
while not isPrime(num):
num+=2
count+=1
primeList.append(num)
num+=2
if count==2000:
break
def test():
sum=2
print '2,'
num=3
while num<2000000:
if not isPrime(num):
num+=2
continue
#print num
sum+=num
num+=2
print 'sum=',sum
def getPrimeFactors(num):
'''
return the prime factors for a number. e.g:
input 10
output: dict = { 2: 1, 5: 1}
'''
factors = {}
prime = 2
while num>1:
while num % prime ==0:
if prime in factors:
factors[prime] = factors[prime]+1
else:
factors[prime] = 1
num = num / prime
prime += 1
while isPrime(prime) == False:
prime +=1
if prime > num:
break;
#print factors
return factors
#!/usr/bin/python
# Filename: Euler7.py
#By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.
#What is the 10001st prime number?
from myUtil import isPrime
count=1
num=3
print count,'2'
while True:
while not isPrime(num):
num+=2
count+=1
print count,num
num+=2
if count==10001:
break
#print 'b=',b
while b>1:
if a%b ==0:
return False
b-=2
return True
'''
num = 600851475143
max_p_factor = 3
a=max_p_factor+2
# to find the next prime factor
while True:
#to find the next bigger prime number
while not isPrime(a):
if a>=num:
break # found result: max_p_factor
else:
a+=2
if a>=num:
break # found result: max_p_factor
elif num%a==0:
max_p_factor=a
num = num/a # a bug: need to loop here!
if a>=num:
break
print 'found one prime factor=',a
else:
print 'prime, but not factor', a
a+=2
