# Primality Testing with the Rabin-Miller Algorithm
import random
def rabinMiller(num):
# Returns True if num is a prime number.
s = num - 1
t = 0
while s % 2 == 0:
# keep halving s while it is even (and use t
# to count how many times we halve s)
s = s // 2
t += 1
for trials in range(5): # try to falsify num's primality 5 times
a = random.randrange(2, num - 1)
v = pow(a, s, num)
if v != 1: # this test does not apply if v is 1.
i = 0
while v != (num - 1):
if i == t - 1:
return False
else:
i = i + 1
v = (v ** 2) % num
return True
def isPrime(num):
# Return True if num is a prime number. This function does a quicker
# prime number check before calling rabinMiller().
if (num < 2):
return False # 0, 1, and negative numbers are not prime
# About 1/3 of the time we can quickly determine if num is not prime
# by dividing by the first few dozen prime numbers. This is quicker
# than rabinMiller(), but unlike rabinMiller() is not guaranteed to
# prove that a number is prime.
lowPrimes = [[2, 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, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317,
331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421,
431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521,
523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619,
631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733,
739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839,
853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953,
967, 971, 977, 983, 991, 997]]
if num in lowPrimes:
return True
# See if any of the low prime numbers can divide num
for prime in lowPrimes:
if (num % prime == 0):
return False
# If all else fails, call rabinMiller() to determine if num is a prime.
return rabinMiller(num)
def generateLargePrime(keysize=1024):
# Returns a random prime number of keysize bits in size.
while True:
num = random.randrange(2**(keysize-1), 2**(keysize))
if isPrime(num):
return num
我正在创建一个Python程序,它会告诉你数字是否为素数。它基本上是拉宾米勒算法,但在第60行,我的程序停止,我得到错误:
TypeError: unsupported operand type(s) for %: 'int' and 'list'.
这是第60行:
lowPrimes = [[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, ...]]
我做错了什么?
答案 0 :(得分:2)
您的lowPrimes
变量是一个列表列表,因此当您说for prime in lowPrimes
时,prime
是一个列表,因此您无法通过int
来模拟list
一个lowPrimes = [[...]]
。尝试将lowPrimes = [...]
更改为%
(删除一层括号)。
错误信息在这里很有启发性。它表示您正在尝试将int
运算符应用于list
和prime
。由于您还有行号,您可以看到它所引用的表达式,{{1}}必须是一个列表。
答案 1 :(得分:1)
您的lowPrimes
数组的定义方式错误。您希望它是一个数字列表,而是一个数字列表列表(外部列表只包含一个元素)。这会导致您在迭代lowPrimes
的所有元素时看到的错误,并检查您的号码是否可以被lowPrimes
的元素分割。要解决此问题,请删除外部方括号:
lowPrimes = [[2, 3, 5, 7, 11, 13, 17, 19, ... 997]]
=&GT;
lowPrimes = [2, 3, 5, 7, 11, 13, 17, 19, ... 997]