Question

从此脚本获取错误的输出。

#!/usr/bin/python

numbers = [1,3,5,7,8,25]


def primes():
    for i in numbers:
        if i > 1:
            if (i % 2) == 0:
                print "not prime"
            else :
                print "prime"

print primes（）

它说25是素数，任何想法为什么？

Answer 1

您的程序正在检查数字是否为奇数，而不是它们是否为素数。这是您想要的验证（来自this page）

# prime numbers are greater than 1
if num > 1:
   # check for factors
   for i in range(2,num):
       if (num % i) == 0:
           print(num,"is not a prime number")
           print(i,"times",num//i,"is",num)
           break
   else:
       print(num,"is a prime number")

Answer 2

import math

numbers = [1,3,5,7,8,25]

def primes(n):
        if n == 2:
            return True
        if n%2 == 0 or n <= 1:
            return False
        sqr = int(math.sqrt(n)) + 1
        for divisor in range(3, sqr, 2):
            if n%divisor == 0:
                return False
        return True

for i in numbers:
    print i, '\t', primes(i)

Answer 3

您的代码只会检查奇数或偶数。不是素数。

我从素数脚本输出不正确

3 个答案: