project euler之素数的总和

Posted 2020-12-02 chif

#这是自己的解法 比较无脑
import math
sum = 0
num = 1
while num<2000000:
    num +=1
    if num > 1:
        for i in range(2, int(math.sqrt(num))+1):
            if (num % i) == 0:
                break
        else:
            print(num, "是质数")
            sum += num
    else:
        print(num, "不是质数")
print(sum)

#这是别人的解法 只需要7行代码 值的学习 且运算速度也比自己的快n多倍
from functools import reduce
p, np = [], set()
for i in range(2,2000001):
    if i not in np:
        p.append(i)
        np.update(range(i**2, 2000001, i))
print(reduce(lambda x,y:x+y,p))