diff options
Diffstat (limited to 'Demo/scripts/fact.py')
| -rwxr-xr-x | Demo/scripts/fact.py | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/Demo/scripts/fact.py b/Demo/scripts/fact.py index ba75a04..6aac414 100755 --- a/Demo/scripts/fact.py +++ b/Demo/scripts/fact.py @@ -1,7 +1,9 @@ #! /usr/local/python -# Factorize numbers, slowly. -# This version uses plain integers and is thus limited to 2**31-1. +# Factorize numbers. +# The algorithm is not efficient, but easy to understand. +# If there are large factors, it will take forever to find them, +# because we try all odd numbers between 3 and sqrt(n)... import sys from math import sqrt @@ -17,13 +19,13 @@ def fact(n): res.append(2) n = n/2 # Try odd numbers up to sqrt(n) - limit = int(sqrt(float(n+1))) + limit = sqrt(n+1) i = 3 while i <= limit: if n%i = 0: res.append(i) n = n/i - limit = int(sqrt(float(n+1))) + limit = sqrt(n+1) else: i = i+2 res.append(n) @@ -32,12 +34,12 @@ def fact(n): def main(): if len(sys.argv) > 1: for arg in sys.argv[1:]: - n = int(eval(arg)) + n = eval(arg) print n, fact(n) else: try: while 1: - n = int(input()) + n = input() print n, fact(n) except EOFError: pass |