python 求1-100的和 求1-2+3-4+5.。。。99的和

 

#求1-100的所有數的和

n = 1
s = 0
while n < 101:
    s = s + n
    n = n + 1
    
print(s)



"""
#求1-2+3-4+5...99的所有數的和
n = 1
s = 0 # s是之前所有數的總和
while n < 100:
    temp = n % 2
    if temp == 0:
        s = s -n
    else:
        s = s + n
    n = n + 1
    
print(s)
"""