某数据压缩方法描述如下：
1）原始数据中，某数不为0且相邻无重复，压缩数据用该数据表示：
2）原始数据中，某数为0且相邻无重复，压缩数据用两个数表示，均为0；
3）原始数据中，某数据相邻有重复，压缩数据用3个数表示：第1个为0，第2个为重复数的个数，第3个数为该数本身。
原始数据：25  0  78  78  78  78  78  78
压缩数据：25  0 0 0  6  78
程序运行界面如下图所示：

根据上述算法，小明编写如下VB程序。
（1）若文本框Text1中输入数据为“0,25,0,78,78,0,0”（不含引号），点击“压缩”命令按钮，在文本框Text2输出数据里有 个0。
（2）实现上述功能的VB程序如下。请在划线处填入合适代码。
Dim a(1 To 100) As Integer, b(1 To 100) As Integer, c(1 To 100) As Integer
Dim n As Integer, num As Integer
Private Sub Init1()
Dim s1 As String, c1 As String
Dim i As Integer, t As Integer, len1 As Integer
n = 0: t = 0: s1 = Text1.Text
len1 = Len(s1)
For i = 1 To len1
ch = Mid(s1, i, 1)
If ch <> "," Then
 ①  
Else
n = n + 1: a(n) = t: t = 0
End If
Next i
n = n + 1: a(n) = t
End Sub
Private Sub Command1_Click()
Call Init1
Dim pa As Integer, pb As Integer
Dim firstdata As Integer, count As Integer, i As Integer
pb = 1
firstdata = a(1)
n = n + 1
a(n) = a(n - 1) + 1
count = 1
For i = 2 To n
If a(i) = firstdata Then
    count = count + 1
Else
If count = 1 Then
If firstdata > 0 Then
b(pb) = firstdata: pb = pb + 1
Else
b(pb) = 0: b(pb + 1) = 0: pb = pb + 2
End If
Else
b(pb) = 0
b(pb + 1) = count
 ②  
pb = pb + 3
End If
count = 1
firstdata = a(i)
End If
Next i
Text2.Text = Str(b(1))
For i = ③
Text2.Text = Text2.Text + "," + Str(b(i))
Next i
End Sub