python --while 练习4
#计算1-2+3-4+5-6……100
#!/usr/bin/env python
#-*- coding:utf8 -*-
num = 1
sum = 0
while num <= 100:
if num % 2 != 0:
sum -= num
else:
sum += num
num += 1
print(sum)
#计算1-2+3-4+5-6……100
#!/usr/bin/env python
#-*- coding:utf8 -*-
num = 1
sum = 0
while num <= 100:
if num % 2 != 0:
sum -= num
else:
sum += num
num += 1
print(sum)