'''
已知一组数据规律如下:
1,-2,3,-4,5,-6,7,-8.......-100
求出这些数字加起来的和 sum=1-2+3-4......-100
'''
l=[]
for i in range(1,101):
if i%2 ==0:
l.append(-i)
else:
l.append(i)
print(sum(l))
'''
已知一组数据规律如下:
1,-2,3,-4,5,-6,7,-8.......-100
求出这些数字加起来的和 sum=1-2+3-4......-100
'''
l=[]
for i in range(1,101):
if i%2 ==0:
l.append(-i)
else:
l.append(i)
print(sum(l))