#!/usr/bin/env python

import time
import operator

def fact(x):
    if x == 0: return 1
    ret = x
    while x > 1:
        x -= 1
        ret *= x
    return ret

def fact_r(x): return reduce(operator.mul, xrange(2, x+1))

def fact_l(x): return reduce(lambda x, y: x*y, xrange(2, x+1))

def time_perf(x, func, count=500):
    start = time.time()
    for i in xrange(count):
        func(x)
    end = time.time()
    return (end - start) / count

print "Fact simple"
print time_perf(500, fact)
print "Fact reduce"
print time_perf(500, fact_r)
print "Fact lambda"
print time_perf(500, fact_l)