第一步：设两数为a、b，且令a>b；

第二步：a÷b，令r为所得余数，若r=0，算法结束，b 即为最大公约数；若r>0则a←b，b←r，并返回第二步；
第三步： 即为 约分后的最简形式。

编写VB程序，程序运行界面如图1所示，请根据算法将下列程序补充完整。

Private Sub Command1_Click()

 Dim a As Integer, b As Integer, r As Integer 'a、b为分子和分母，r为最大公约数

 a = Val(Text1.Text)

 b = Val(Text2.Text)

 If b = 0 Then c = MsgBox("分母不能为0"): Exit Sub

 '如果分母为0，则提示“分母不能为0”并退出该过程

 r = {#blank#}1{#/blank#} 

 Text3.Text = Str(a / r)

 Text4.Text = Str(b / r)

End Sub

Function gys(ByVal m As Integer, ByVal n As Integer) As Integer

'gys函数用于求最大公约数

Dim s As Integer

 If m < n Then

    t = m: m = n: n = t

 End If

 Do While n <> 0

    s = m Mod n

    m = n

    n = s

 Loop

{#blank#}2{#/blank#}   

End Function

Private Sub Command1_Click()

Dim a As Integer, b As Integer

a = 5: b = 3

Print work(a, b)

End Sub

Function work(x As Integer, y As Integer) As Integer

If (x < y) Then

work = 0

Exit Function

End If

If (y = 0) Then

work = 1

Exit Function

End If

work = work(x - 1, y - 1) + work(x - 1, y)

End Function

参赛班级用数字1，2，3，4……number表示，依次存入数组a(1)～a(number)，若1号班级的编号为5，则a(1)=5。

Private Sub Command1_Click()

  Dim y As Long

  Text1.Text = ""

  y = f(3)

  Label1.Caption = Str(y)

End Sub

Function f(n As Integer) As Long

    Text1.Text = Text1.Text + Str(n)

    If n <= 1 Then

       f = 1

    Else

       f = f(n - 1) + 2

    End If

End Function