用于在Python中查找第1000个素数的麻省理工学院开放课程代码不起作用?

时间:2014-04-23 04:45:04

标签: python

我刚刚开始编程,我的第一个个人任务是找到第1000个素数。我认为这段代码是正确的,但它列出了前1000个奇数。有什么见解吗?

count = 1
num = 3
prime = [2]

while count <= 1000:
    for x in range(2, num + 1):
        if num % x == 0 and num == x:
            prime.append(num)
            num += 2
    count += 1

print(prime[1000])

2 个答案:

答案 0 :(得分:0)

我刚刚写了这篇文章。它会问你有多少素数用户想看,在这种情况下它会是1000.随意使用它:)。

# p is the sequence number of prime series
# n is the sequence of natural numbers to be tested if prime or not
# i is the sequence of natural numbers which will be used to devide n for testing
# L is the sequence limit of prime series user wants to see
p=2;n=3
L=int(input('Enter the how many prime numbers you want to see: '))
print ('# 1  prime is 2')
while(p<=L):
    i=2
    while i<n:
        if n%i==0:break
        i+=1
    else:print('#',p,' prime is',n); p+=1
    n+=1 #Line X

#when it breaks it doesn't execute the else and goes to the line 'X' 

答案 1 :(得分:-1)

import math

def is_prime(a):
    for i in xrange(2, int(math.sqrt(a)+1)):
        if a%i == 0:
            return False
    return True

primes=[]
count = 2
while len(primes) < 1000:
    if is_prime(count):
        primes.append(count)
    count += 1

print(primes)`