循环结构练习

"""

输入一个正整数判断它是不是素数

Version: 0.1
Author: 骆昊
Date: 2018-03-01

"""

from math import sqrt

num = int(input('请输入一个正整数: '))
end = int(sqrt(num))
is_prime = True
for x in range(2, end + 1):
	if num % x == 0:
		is_prime = False
		break
if is_prime and num != 1:
	print('%d是素数' % num)
else:
	print('%d不是素数' % num)

"""

输入两个正整数计算最大公约数和最小公倍数

Version: 0.1
Author: 骆昊
Date: 2018-03-01

"""

x = int(input('x = '))
y = int(input('y = '))
if x > y:
	(x, y) = (y, x)
for factor in range(x, 0, -1):
	if x % factor == 0 and y % factor == 0:
		print('%d和%d的最大公约数是%d' % (x, y, factor))
		print('%d和%d的最小公倍数是%d' % (x, y, x * y // factor))
		break

"""

打印各种三角形图案

*
**
***
****
*****

    *
   **
  ***
 ****
*****

    *
   ***
  *****
 *******
*********

Version: 0.1
Author: 骆昊
Date: 2018-03-01

"""

row = int(input('请输入行数: '))
for i in range(row):
    for _ in range(i + 1):
        print('*', end='')
    print()


for i in range(row):
    for j in range(row):
        if j < row - i - 1:
            print(' ', end='')
        else:
            print('*', end='')
    print()

for i in range(row):
    for _ in range(row - i - 1):
        print(' ', end='')
    for _ in range(2 * i + 1):
        print('*', end='')
    print()