请高手 帮助 用c 或 VB 编写 一 凑数问题 具体问题如下…………
请高手 帮助 用c 或 VB 编写 一 凑数问题 具体问题如下…………编写一程序，从键盘输入数字R，计算机自动检查在下列算式的（）中能否天上“+”或“—”凑成相应的等式。如能凑成，则打印出这些算式；如凑不成，则给出信息“NO answer！”1（）2（）3（）4（）5（）6（）7（）8（）9=R
2\仅限 加减号不 ?
如果是没括号,仅限 加减号, 可以试着写一下.
程序代码：Option Explicit
Private Type 临时结果结构
算式 As String
结果 As Long
End Type
Dim 缓存(0 To 255) As 临时结果结构
Dim 缓存计数 As Long
Private Sub Command1_Click()
Dim i As Long
i = Val(Text1.Text) '输入值
Dim o As Long
o = 计算(i) '计算
If o = -1 Then '如果计算失败
Text2.Text = "NO answer！" '提示
Else '否则显示表达式及结果
Text2.Text = 缓存(o).算式 & "=" & 缓存(o).结果
End If
End Sub
Private Function 计算(cs As Long) As Long
Dim i As Long
For i = 0 To 缓存计数 '查找缓存,减少计算
If 缓存(i).结果 = cs Then '在缓存中找到,
计算 = i '那么直接返回结果
Exit Function
End If
Next i
Dim j As Long
Dim k As String, m As String
Dim o As Long
For i = 缓存计数 To 255 '计算,一共有 8 个符号位,每位用 1位为代替, 1 为加, 0 为减
k = HextoBin(CByte(i)) '转化为二进制,用来取位
m = "1" '第一个数
o = 1
For j = 2 To 9 '第二个数 到第 9 个数
If Mid(k, j - 1, 1) = 1 Then '根据符号位进行计算,组合表达式
m = m & "+" & j
o = o + j
Else
m = m & "-" & j
o = o - j
End If
Next j
缓存(i).算式 = m '如果计算结果与参数相符,那么停止计算,输出结果
缓存(i).结果 = o
缓存计数 = i '保存缓存的最大值,可以减少计算次数
If o = cs Then
计算 = i '返回结果
Exit Function
End If
Next i
缓存计数 = i '没找到结果,保存缓存
计算 = -1 '返回没结果
End Function
Private Function HextoBin(cs As Byte) As String
'BYTE数值转 二进制字符串
Dim i As Long, j As String
Dim m As String
j = Hex(cs)
If Len(j) = 1 Then j = "0" & j
For i = 1 To 2
Select Case Mid(j, i, 1)
Case "0"
m = m & "0000"
Case "1"
m = m & "0001"
Case "2"
m = m & "0010"
Case "3"
m = m & "0011"
Case "4"
m = m & "0100"
Case "5"
m = m & "0101"
Case "6"
m = m & "0110"
Case "7"
m = m & "0111"
Case "8"
m = m & "1000"
Case "9"
m = m & "1001"
Case "A", "a"
m = m & "1010"
Case "B", "b"
m = m & "1011"
Case "C", "c"
m = m & "1100"
Case "D", "d"
m = m & "1101"
Case "E", "e"
m = m & "1110"
Case "F"
m = m & "1111"
End Select
Next i
HextoBin = m
End Function
