Question

VB打印单位矩阵

键盘输入正整数n打印n*n的单位矩阵，这道题有三个答案，但是运行后有三个结果，请问高手有什么不同？哪个是正确的？
第一个:
Private Sub Command3_Click()
Dim n As Integer
Dim i, j As Integer
n = Val(InputBox("输入正整数"))
For i = 1 To n
For j = 1 To n
Print 1 + Int(Rnd() * 99);
Next
Print
Next
End Sub
第二个：
Private Sub Command4_Click()
n = Val(InputBox("请输入N值"))
For i = 1 To n * n
Print Int(10 * Rnd);
If i Mod n = 0 Then Print
Next
End Sub
第三个：
Private Sub Command5_Click()
Dim a() As Long, n As Long, temp As String
Dim i&, j&, s&, limit&, direct%

n = Val(Trim(InputBox("输入n：", , 5)))
ReDim a(1 To n, 1 To n) As Long
direct = 0
i = 1: j = 1: s = 1
a(1, 1) = 1
Do While s < n * n
Select Case direct
Case 0
a(i + 1, j) = a(i, j) + 1: i = i + 1
If i + 1 > n - limit Then direct = 1
Case 1
a(i, j + 1) = a(i, j) + 1: j = j + 1
If j + 1 > n - limit Then direct = 2
Case 2
a(i - 1, j) = a(i, j) + 1: i = i - 1
If i - 1 < 1 + limit Then direct = 3: limit = limit + 1
Case 3
a(i, j - 1) = a(i, j) + 1: j = j - 1
If j - 1 < 1 + limit Then direct = 0
End Select
s = s + 1
Loop

For i = 1 To n
For j = 1 To n
temp = Trim(Str(a(i, j)))
Print temp; String(Len(Trim(Str(n * n))) - Len(temp) + 1, " ");
Next
Print
Next
Print

End Sub

Answer 1

他们全部都是n*n的单位矩阵，从你的要求来说都是正确的。

区别：
1:生成矩阵中的元素是随机生成的，并且是1-99的数
2:生成矩阵中的元素是随机生成的，生成0-9以内的数
3:矩阵中的元素是1 2 3 4 …… 一直排列到N*N,并且数的顺序是 从左上角左内旋转的顺序排列。 如下图
│┌—┐
│└┘│
└——┘