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Summation of primes

是我算法不对,还是笔记本CPU太差?

我优化了两次,还是花了三四个小时来得到结果。

在输出上加1就是最终结果。

The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.

Find the sum of all the primes below two million.

def isprime(n):
    boolisprime = True
    for i in xrange(3,n):
        if n % i == 0:
            boolisprime = False
            break
    return boolisprime

def primenumber(n):
    i = 1
    sumprime = 0
    while True:
        if isprime(i) == True:
            sumprime += i
            print i,sumprime
        if i > n:
            break
        i += 2
    return sumprime
print primenumber(2000000)+1