from math import sqrt
import time

def mrange(start, stop, step=1):
    i = start
    while i < stop:
        yield i
        i += step

def is_prime(n):
    return all(n % i for i in mrange(3, int(sqrt(n)) + 1, 2))

primes = [3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251]


p = 127
q = 193

n = p*q


def loop_nolist():
    for x in range(3, 256, 2):
        if( is_prime(x) and (n/x) < 256 and is_prime(n/x) and n == (x * (n/x)) ):
            ## print("n=" + str(n) + "\tp=" + str(x) + "\tq=" + str(n/x))
            break

def loop_list():
    for x in primes:
        if( (n/x) < 256 and (n/x) in primes and n == (x * (n/x)) ):
            ## print("n=" + str(n) + "\tp=" + str(x) + "\tq=" + str(n/x))
            break


times = []
for x in range(0, 100):
    oTime = time.time();
    loop_nolist()
    times.append(time.time() - oTime)

print( "Average time for scanning without list\t" + str( sum(times)/len(times) ) )

times = []
for x in range(0, 100):
    oTime = time.time();
    loop_list()
    times.append(time.time() - oTime)

print( "Average time for scanning with list\t" + str( sum(times)/len(times) ) )