Question

vb编程：求a=1+3+5+。。。+（2n-1）的值

Private Sub Form_click()
Dim a As Integer
Dim i As Integer
Dim n As Integer
n = InputBox("n=")
For i = 1 To n
a = a + 2 * n - 1
Next i
Print "n="; n, "a="; a
End Sub
怎么不对呢？

Answer 1

Private Sub Form_click()
Dim a As Integer
Dim i As Integer
Dim n As Integer
n = InputBox("n=")
For i = 1 To n
a = a + 2 * i - 1 //这里应该是i而不是n，否则你求出来的答案就是2n-1 + 2n-1 + ... + 2n-1了
Next i
Print "n="; n, "a="; a
End Sub

Answer 2

直接在for循环中把a=a+2*n-1替换成a=a+2*i-1就OK
原因你细想一下就明白了,你要的是一次一次的加直到2n-1为止,而不是每次都加上2n-1

Answer 3

for 循环修改下
for i=1 to 2n-1 step 2
a=a+i
next i

Answer 4

a=a+2*n-1应该是a=a+2*i-1

Answer 5

抱歉刚才错了1