十三、        请你设计一个程序，对于从键盘输入的任意一个四位数，把它表示成连续自然数之和的形式。例如： 1998=498+499+500+501 。请你找出所有可能的组合。
答：
源程序：
Private Sub Command1_Click()
Dim x As Integer, y As Integer, z As Integer, s As String
x = CInt(Trim(Text1.Text))
If x < 1000 Or x > 9999 Then
    MsgBox "您所输入的不是四位数!请重新输入!"
    Text1.Text = ""
    Text1.SetFocus
    Exit Sub
End If
y = x \ 4
z = x Mod 4
s = ""
If z = 2 Then
    s = y - 1 & "  " & y & "  " & y + 1 & "  " & y + 2
Else
    s = "找不到连续的四个自然数!"
End If
Text2 = s
End Sub

Private Sub Command2_Click()
Dim i As Integer, j As Integer, m As Integer, n As Integer
j = 0
For i = 1000 To 9999
    m = i \ 4: n = i Mod 4
    If n = 2 Then
        j = j + 1
        Text3 = Text3.Text & i & "  "
        If j Mod 10 = 0 Then Text3.Text = Text3.Text & vbCrLf
    End If
Next i
End Sub

十四、       寻找平方数对
请你设计一个程序，对于从键盘输入的自然数N，找出所有小于N且满足下述条件的数对（X，Y）：X+Y和X-Y都是完全平方数。例如：当X=10，Y=6时，有10+6=16=4²     10-6 =4=2²
答：
源程序：
Private Sub Command1_Click()
Dim i As Long, j As Long, n As Long
n = Int(Trim(Text1.Text))
List1.Clear
List1.AddItem "符合条件的平方数对有："
For i = n - 1 To 2 Step -1
    For j = i - 1 To 1 Step -1
        If pfs(i + j) And pfs(i - j) Then List1.AddItem "（" & i & "，" & j & "）"
    Next j
Next i
End Sub
Private Function pfs(ByVal x As Long) As Boolean
If Int(Sqr(x)) ^ 2 = x Then
    pfs = True
Else
    pfs = False
End If
End Function

十五、       请你设计程序，对于给定的自然数N确定满足下述关系的最小数S。S可以表示为两对不同的自然数的n次方幂之和。即找出最小数S，使得：S=aⁿ+bⁿ=cⁿ+dⁿ
这里的a，b，c，d都是自然数，切a≠c，b≠d
例如，当n=2时，有S=50=1²+7²=5²+5²
当n=3时，有S=1729=1³+12³=9³+10³
答：
源程序：
Private Sub Command1_Click()
Dim i As Long, j As Long, n As Integer, l As Integer, s As Long, t As Long
s = 1
n = Int(Trim(Text1.Text))
Text2.Text = ""
Do
    l = 0
    t = findmax(s, n)
    For i = 1 To t
        For j = i To t
            If i ^ n + j ^ n = s Then l = l + 1
            If l = 2 Then Text2.Text = "最小数S为：" & s: Exit Do
        Next j
    Next i
    s = s + 1
Loop Until (l = 2)
End Sub
Private Function findmax(ByVal x As Long, ByVal y As Long)
Dim i As Long
For i = 1 To x
    If i ^ y > x Then Exit For
Next i
findmax = i - 1
End Function
Private Sub Command2_Click()
Text1.Text = ""
Text2.Text = ""
Text1.SetFocus
End Sub

十六、豆子下落问题
如图所示一个容器，有1000粒豆子从入口一个一个地落下，通过六层隔板落入下面7个格子，豆子经过隔板向左右两个方向的机会相等，编一个程序计算每个格子中豆子的数目。
答：
 非常抱歉，下载题目时没有注意到图，故无法按实际情况做出一个明确的答案，敬请原谅！读者可以自行发挥想象！