求和:1-2+3-4+5-6+..........怎么编
请你发到我的邮箱.zengjb1211@163.com 谢谢!.....................

急用!!!!!!!!!!!!!!!!!

太简单了吧

你发给我啊!!!!!!!!!!!!!!!
谢谢了

我是新手
我刚学不到一月

Dim n As Integer = CInt(TextBox1.Text)
Dim a As Integer
Dim sum As Integer
For a = 1 To n
If a Mod 2 = 0 Then
sum -= a
Else
sum += a
End If
Next
MessageBox.Show(sum)