[求助]拜请各位大虾有关下标越界的问题！！！感激涕零

dance · 发表于 2006-5-12 15:51:00

我在编一个求点集凸包的程序
采点集的程序部分已经搞定了但到了去极点部分就老提示下标越界
下面是我的程序：
Option Explicit
Private Type pointinfo
x As Single                   '点的x 坐标值
y As Single                   '点的y 坐标值
q As Single                   '与水平线的夹角
End Type
Dim p0 As pointinfo
Dim p(1 To 200) As pointinfo '点集
Dim ps(1 To 200) As pointinfo '排序后的点集
Dim pi(1 To 200) As pointinfo '极点
Dim n, m, d As Integer
Dim x0, y0 As Single
Dim l, e As Integer
Private Sub Form_MouseDown(Button As Integer, Shift As Integer, x As Single, y As Single)
DrawWidth = 4
If n = 0 Then
p0.x = x
p0.y = y
Circle (x, y), 100, RGB(255, 0, 255)
Else '输入点集
p(n).x = x
p(n).y = y
Circle (x, y), 10, RGB(255, 255, 0)
End If
n = n + 1
x0 = x
y0 = y
End Sub

Private Sub Command2_Click()
Dim i As Integer
Dim q As Single
p(n).x = x0
p(n).y = y0
Const pi = 3.14
For i = l To n
If p(i).y - p0.y = 0 Then       （总是在这句提示下标越界）
      If p(i).x - p0.x = 0 Then
         p(i).q = 90
      ElseIf p(i).x - p0.x > 0 Then
      p(i).q = 180 / pi * Atn((p(i).y - p0.y) / (p(i).x - p0.x))
      Else
         p(i).q = 180 / pi * Atn((p(i).y - p0.y) / (p(i).x - p0.x)) + 180
      End If
ElseIf p(i).y - p0.y  0 Then
      p(i).q = 360 + 180 / pi * Atn((p(i).y - p0.y) / (p(i).x - p0.x))
      Else
      p(i).q = 180 + 180 / pi * Atn((p(i).y - p0.y) / (p(i).x - p0.x))
      End If
End If

Next i
End Sub