euler/e003.py
Correl Roush 12c5dd7875 Documented each exercise, and placed executable code in a main() function.
git-svn-id: file:///srv/svn/euler@63 e5f4c3ec-3c0c-11df-b522-21efaa4426b5
2010-05-04 18:21:07 +00:00

22 lines
486 B
Python

"""Find the largest prime factor of a composite number.
The prime factors of 13195 are 5, 7, 13 and 29.
What is the largest prime factor of the number 600851475143 ?
"""
def pfactor(n):
i = 2
while (n % i != 0 and i < n):
i = i + 1
if i == n:
return [n]
p = pfactor(n // i)
p.append(i)
return sorted(p, reverse=True)
def main():
print 'Prime factors of 600851475143:'
print pfactor(600851475143)
if __name__ == '__main__':
main()