用Python实现求最大公约数和判断是否是素数

[python] 

#!/usr/bin/env python  

  

def showMaxFactor(num):  

    count = num / 2   

    while count > 1:  

        if num % count == 0:  

            print 'largest factor of %d is %d' % (num, count)  

            break        #break跳出时会跳出下面的else语句  

        count -= 1  

    else:  

        print num, "is prime"  

  

for eachNum in range(10,21):  

    showMaxFactor(eachNum)  

 

输出如下:

largest factor of 10 is 5

11 is prime

largest factor of 12 is 6

13 is prime

largest factor of 14 is 7

largest factor of 15 is 5

largest factor of 16 is 8

17 is prime

largest factor of 18 is 9

19 is prime

largest factor of 20 is 10