计算机VB考试题参考.pdf

1

过程函数：

501. 有一个数列，前三项都是 1，从第四项开始，每一项都是其相邻前三项之

和的 1/2 。试编写函数过程，求数列前 n 项的平均值。要求调用该过程，计算并

输出 n=20 时前 n 项的平均值（保留 4 位小数）。

结果： 10.1278

Function f( ByVal n As Integer ) As Double

Dim f1, f2, f3, fn, s As Double

f1 = 1

f1 = f2

f2 = f3

f3 = fn

Next

f = s / n

End Function

Private Sub Button1_Click( ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles Button1.Click

Dim n As Integer

Dim a As Double

计算并输出 n=40 时前 n 项的和（保留 4 位小数）。

结果： 224.1111

Function fs( ByVal n As Integer ) As Double

Dim f1, f2, f3, fn, s As Double

f1 = 3

f2 = 5

f3 = 7

s = f1 + f2 + f3

For n = 4 To n

fn = (f1 + f2 + f3) / 3

2

f1 = f2

f3 = fn

Next

fs = s

End Function

Private Sub Button1_Click( ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles Button1.Click

Dim n As Integer

503. 有一个数列，前三项都是 1，从第四项开始，每一项都是其相邻前三项

之和的 1/2 。试编写函数过程，求数列第 n项的值。要求调用该过程，计算并输

出n=30时前 n项的和。 ( 保留 3位小数）

结果： 1756.372

Function f( ByVal n As Integer ) As Double

f1 = 1

f2 = 1

f3 = 1

End Function

Private Sub Button1_Click( ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles Button1.Click

Dim n As Integer

Dim s As Double

For n = 1 To 30

s = s + f(n)

Next

MsgBox(Format(s, "0.000" ))

End Sub

3

504. 有一个数列，其前三项分别为 1、2、3，从第四项开始，每项均为其相邻

计算并输出 n=20时前n项的平均值。 ( 保留 5位小数）

结果： 22.73083

Function f( ByVal n As Integer ) As Double

Dim f1, f2, f3, fn As Double

f1 = 1

f2 = 2

f3 = 3

Next

f = fn

End Function

Private Sub Button1_Click( ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles Button1.Click

Dim s, v As Double

For n = 1 To 20

s = s + f(n)

Next

之间满足条件的数据的个数。

结果： 30

Function f(ByVal n as integer) As Boolean

Dim i, j, k As Integer

i = n \ 1000

j = n Mod 100

k = (n Mod 1000) \ 100

If (i Mod 7 = 0) And (j Mod 7 = 0) And (k Mod 7 = 0) Then

f = True

Else