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（加试题）小王设计了一个算法试图求出平面坐标系中最左点出发，从左往右途经所有点到达最右点的路径值和，编写了一个VB程序功能如下：在文本框Text1中输入需随机生成的坐标点数量，单击“生成”按钮Command1后，在列表框List1中生成相应数量的坐标点（坐标值为大于等于1小于10的实数 ，保留一位小数），在文本框Text2中输出路径值。程序界面如图所示。

实现上述功能的VB程序如下，但划线部分代码有错，请改正。
Private Sub Command1_Click()
Dim x(1 To 100) As Single, y(1 To 100) As Single
Dim tmp As Single, length As Single, sum As Single, x1 As Single, y1 As Single
Dim i As Integer, j As Integer, k As Integer
Randomize 
List1.Clear
k = Val(Text1.Text)
For i = 1 To k
x(i) = Int(Rnd * 90) / 10 + 1
y(i) = Int(Rnd * 90) / 10 + 1
List1.AddItem "X:" + Str(x(i)) + "   " + "Y:" + Str(y(i))
Next i
For i = 1 To k - 1
For j = 1 To k - i
If x(j) > x(j + 1) Then
x(i)=x(i) + x(j)
x(j) = x(i) - x(j)
 x(j) = x(i) + x(j)   答：________________
tmp = y(j)
y(j) = y(j + 1)
y(j + 1) = tmp
End If
Next j
Next i
sum = 0: length = 0
For i = 1 To k - 1
 x1 = (x(i) - x(1)) ^ 2     答:______________    
'变量y1计算方法同x1，代码略
length = Sqr(x1 + y1)
sum = sum + length
Next i
Text2.Text = Str(Int(sum * 10) / 10)
End Sub