散分。

[SYSSZ]

请用代码将字符串"2x(3-4x)+5(8+3x+8x^2)=(x^2+2)5x-3x^2(2x-7)"
变为字符串"6x-8x^2+40+15x+40x^2=5x^3+10x-6x^3+21x^2"
其中^表示乘方,也就是去括号.
顶贴有分.

[cqq_chen]

顶一下

[孤独剑_LPZ]

[Quote=引用 3 楼 myjian 的回复:]
.......算法是最能让我郁闷的事情之一......飘走.....
[/Quote]
头疼,顶了

[king06]

很多时候还是人脑好使啊

[bluesky396]

帮顶。。。

[s11ss]

难

[ltq88]

jf

[wuwenchun168]

顶！！！！！顺便接分~

[bj0629]

jf

[贝隆]

顶

[SYSSZ]

快来接分！

[fly896403]

[Quote=引用 12 楼 asftrhgjhkjlkttttttt 的回复:]
引用 3 楼 myjian 的回复:
.......算法是最能让我郁闷的事情之一......飘走.....

头疼,顶了
[/Quote]
没疼~~晕了·~~~

[SYSSZ]

[Quote=引用 7 楼 sysdzw 的回复:]
有点小复杂，不要合并同类项吗？
[/Quote]不用合并同类项。

[水猿兵团五哥]

[Quote=引用 18 楼 syssz 的回复:]
引用 7 楼 sysdzw 的回复:
有点小复杂，不要合并同类项吗？
不用合并同类项。
[/Quote]
啥叫同类项？
哈哈
都忘记了这些词

[古今多少事]

老张估计是已经解决了……期待答案！

[fengfeng28]

Dim a, b, c, d, e, x As String
Dim f As Integer
a = "2x(3-4x)+5(8+3x+8x^2)"
f = InStr(1, a, "+")
b = Left(a, f - 1) 'b=2x(3-4x)
c = Mid(a, f + 1, 12) 'c=5(8+3x+8x^2)
Debug.Print c
d = Mid(b, 4, 1) 'd=3
f = Val(d) * Val(Mid(b, 1, 1))
e = f & "x" 'e=6x
f = Val(Mid(b, 1, 1)) * Val(Mid(b, 6, 1))
e = e & "-" & f & "x ^ 2" & "+" 'e=6x-8x^2+
a = Mid(c, 3, 1)
b = Mid(c, 1, 1)
f = Val(a) * Val(b)
e = e & f & "+"
a = Mid(c, 5, 1)
f = Val(a) * Val(b)
e = e & f & "x" & "+"
a = Mid(c, 8, 1)
f = Val(a) * Val(b)
e = e & f & "x^2"
Debug.Print eDim a, b, c, d, e, x As String
Dim f As Integer
a = "2x(3-4x)+5(8+3x+8x^2)"
f = InStr(1, a, "+")
b = Left(a, f - 1) 'b=2x(3-4x)
c = Mid(a, f + 1, 12) 'c=5(8+3x+8x^2)
Debug.Print c
d = Mid(b, 4, 1) 'd=3
f = Val(d) * Val(Mid(b, 1, 1))
e = f & "x" 'e=6x
f = Val(Mid(b, 1, 1)) * Val(Mid(b, 6, 1))
e = e & "-" & f & "x ^ 2" & "+" 'e=6x-8x^2+
a = Mid(c, 3, 1)
b = Mid(c, 1, 1)
f = Val(a) * Val(b)
e = e & f & "+"
a = Mid(c, 5, 1)
f = Val(a) * Val(b)
e = e & f & "x" & "+"
a = Mid(c, 8, 1)
f = Val(a) * Val(b)
e = e & f & "x^2"
Debug.Print e
真是无聊了，呵呵

[unsv29mj]

[Quote=引用 21 楼 fengfeng28 的回复:]
Dim a, b, c, d, e, x As String
Dim f As Integer
a = "2x(3-4x)+5(8+3x+8x^2)"
f = InStr(1, a, "+")
b = Left(a, f - 1)  'b=2x(3-4x)
c = Mid(a, f + 1, 12) 'c=5(8+3x+8x^2)
Debug.Print c
d = Mid(b, 4, 1)      'd=3
f = Val(d) * Val(Mid(b, 1, 1))
e = f & "x"          'e=6x
f = Val(Mid(b, 1, 1)) * Val(Mid(b, 6, 1))
e = e & "-" & f & "x ^ 2" & "+"  'e=6x-8x^2+
a = Mid(c, 3, 1)
b = Mid(c, 1, 1)
f = Val(a) * Val(b)
e = e & f & "+"
a = Mid(c, 5, 1)
f = Val(a) * Val(b)
e = e & f & "x" & "+"
a = Mid(c, 8, 1)
f = Val(a) * Val(b)
e = e & f & "x^2"
Debug.Print eDim a, b, c, d, e, x As String
Dim f As Integer
a = "2x(3-4x)+5(8+3x+8x^2)"
f = InStr(1, a, "+")
b = Left(a, f - 1)  'b=2x(3-4x)
c = Mid(a, f + 1, 12) 'c=5(8+3x+8x^2)
Debug.Print c
d = Mid(b, 4, 1)      'd=3
f = Val(d) * Val(Mid(b, 1, 1))
e = f & "x"          'e=6x
f = Val(Mid(b, 1, 1)) * Val(Mid(b, 6, 1))
e = e & "-" & f & "x ^ 2" & "+"  'e=6x-8x^2+
a = Mid(c, 3, 1)
b = Mid(c, 1, 1)
f = Val(a) * Val(b)
e = e & f & "+"
a = Mid(c, 5, 1)
f = Val(a) * Val(b)
e = e & f & "x" & "+"
a = Mid(c, 8, 1)
f = Val(a) * Val(b)
e = e & f & "x^2"
Debug.Print e
真是无聊了，呵呵
[/Quote]

我太佩服你了 太牛了！！建议楼主把所有的分都给我！

[futosky]

有分好

[slowgrace]

[Quote=引用 29 楼 syssz 的回复:]
引用 27 楼 slowgrace 的回复:
老张，你可以发300分帖么？

当然可以。
[/Quote]

要散就散痛快嘛

[神马都能聊]

进来接老张的技术分。

[slowgrace]

'Remove parentheses in a math expression
Private Function RemParen(ByVal strInput As String) As String
    Dim strResult As String
    Dim strIn As String '括号里的表达式'
    Dim strOut As String '括号外的表达式'
    Dim strtmp() As String, i As Long '用于分割'
    Dim lngStartPos As Long, lngEndPos As Long, lngRightParen As Long, lngLeftParen As Long
    Dim strEndSign As String '每段括号后最近的加号或等号'
    
    '把减号替换成+-以便分割
    strInput = Replace(strInput, "-", "+-")
    
    lngStartPos = 1
    '逐括号分段处理'
    Do
        '*****取得括号内部分和括号外部分'
        lngRightParen = InStr(lngStartPos, strInput, ")")
        lngLeftParen = InStr(lngStartPos, strInput, "(")
        strIn = Mid(strInput, lngLeftParen + 1, lngRightParen - lngLeftParen - 1)
        If lngLeftParen = lngStartPos Then
        '括号部分在前：(x^2+2)5x这种形式的'
            lngEndPos = FindEndSign(lngRightParen, strInput, strEndSign)
            strOut = Mid(strInput, lngRightParen + 1, lngEndPos - lngRightParen - 1)
        Else
        '括号部分在后: 2x(3-4x)这种形式的'
            strOut = Mid(strInput, lngStartPos, lngLeftParen - lngStartPos)
            lngEndPos = lngRightParen + 1
            strEndSign = Mid(strInput, lngEndPos, 1)
        End If
'        Debug.Print strIn, strOut, strEndSign
        
        '*****把括号内部分和括号外部分相乘'
        strtmp = Split(strIn, "+")
        For i = 0 To UBound(strtmp)
            strResult = strResult & MplyStr(strOut, strtmp(i)) & "+"
        Next i
        
        '*****把最后一个字符弄对'
        strResult = Left(strResult, Len(strResult) - 1) & strEndSign
        lngStartPos = lngEndPos + 1
        If strEndSign = "" Then Exit Do
    Loop
   
    strResult = Replace(strResult, "+-", "-")
    RemParen = strResult
    
'    Debug.Print strInput
'    Debug.Print strResult
End Function

'从str1的lngStartPos开始找到其后最近的加号或等号'
'返回值是找到的等号或加号的位置，找不到则返回str1的长度加1'
'找到的等号或加号存在ByRef参数strEndSign里返回，找不到则返回""'
Private Function FindEndSign(ByVal lngStartPos As Long, ByVal str1 As String, _
        ByRef strEndSign As String) As Long
    Dim lngAdd As Long, lngEqual As Long
    
    lngAdd = InStr(lngStartPos, str1, "+")
    lngEqual = InStr(lngStartPos, str1, "=")
                
    If lngAdd = 0 Then lngAdd = 10000
    If lngEqual = 0 Then lngEqual = 10000

    If lngAdd < lngEqual Then
        strEndSign = "+"
        FindEndSign = lngAdd
    Else
        strEndSign = "="
        FindEndSign = lngEqual
    End If
    
    If FindEndSign = 10000 Then
        strEndSign = ""
        FindEndSign = Len(str1) + 1
    End If
End Function

'把str1和str2所表示的表达式"相乘"，并把相乘的结果输出'
'注意：str1，str2都只能是含有0个或1个变量的单项式！变量只能是x!
'可处理的最复杂情况是：MplyStr("3x^2", "-2x") = "-6x^3"
Private Function MplyStr(str1 As String, str2 As String) As String
    Dim strResult As String
    Dim i As Long, j As Long
    Dim str1suf As String, str2suf As String '后缀'
    
    AnaStr str1, i, str1suf
    AnaStr str2, j, str2suf
    
    If str1suf <> "" And str2suf <> "" Then
        strResult = (i * j) & "x^" & (GetPower(str1suf) + GetPower(str2suf))
    Else
        strResult = (i * j) & str1suf & str2suf
    End If
    MplyStr = strResult
End Function

'分析str1，拆分它的数字部分和变量部分'
'数字部分返回到ByRef参数lng1里；变量部分返回到ByRef参数str1suf里'
'比如 str1="-x^2", lng1 = -1, str1suf = "x^2"
Private Sub AnaStr(ByVal str1 As String, ByRef lng1 As Long, ByRef str1suf As String)
    Dim strtmp() As String
    
    On Error GoTo AnaStr_ErrHandler
    str1suf = ""
    strtmp = Split(str1, "x")
    strtmp(0) = Replace(strtmp(0), "+-", "-")
    If strtmp(0) = "" Then
        lng1 = 1
    ElseIf strtmp(0) = "-" Then
        lng1 = -1
    Else
        lng1 = strtmp(0)
    End If
    str1suf = "x" & strtmp(1)
    Exit Sub
    
AnaStr_ErrHandler:
    If Err.Number = 9 Then
    'Subscript out of range
    '没有x
        Resume Next
    Else
        Stop
        Resume
    End If
End Sub


'从带幂的字符串得到对应的幂次
'GetPower("x^2") = 2, GetPower("x") = 1
Private Function GetPower(strPower As String) As Long
    If strPower = "x" Then
        GetPower = 1
    Else
        GetPower = Right(strPower, Len(strPower) - 2)
    End If
End Function

测试函数：

Public Sub test_RemParen()
    Debug.Assert RemParen("2x(3-4x)+5(8+3x+8x^2)=(x^2+2)5x-3x^2(2x-7)") = "6x-8x^2+40+15x+40x^2=5x^3+10x-6x^3+21x^2"
    Debug.Assert RemParen("2x(3-4x)") = "6x-8x^2"
    Debug.Assert RemParen("5(8+3x+8x^2)") = "40+15x+40x^2"
    Debug.Assert RemParen("(x^2+2)5x") = "5x^3+10x"
    Debug.Assert RemParen("-3x^2(2x-7)") = "-6x^3+21x^2"
End Sub

Public Sub Test_MplyStr()
    Debug.Assert MplyStr("2", "3") = "6"
    Debug.Assert MplyStr("2", "-4x") = "-8x"
    Debug.Assert MplyStr("5", "8x^2") = "40x^2"
    Debug.Assert MplyStr("5x", "2") = "10x"
    Debug.Assert MplyStr("3x^2", "7") = "21x^2"
    Debug.Assert MplyStr("3x^2", "2x") = "6x^3"
    Debug.Assert MplyStr("5x", "x^2") = "5x^3"
End Sub

Public Sub test_AnaStr()
    Dim lng1 As Long
    Dim str1suf As String
    
    AnaStr "2", lng1, str1suf
    Debug.Assert lng1 = 2
    Debug.Assert str1suf = ""
    
    AnaStr "-7", lng1, str1suf
    Debug.Assert lng1 = -7
    Debug.Assert str1suf = ""
    
    AnaStr "x", lng1, str1suf
    Debug.Assert lng1 = 1
    Debug.Assert str1suf = "x"
    
    AnaStr "-x", lng1, str1suf
    Debug.Assert lng1 = -1
    Debug.Assert str1suf = "x"
    
    AnaStr "2x", lng1, str1suf
    Debug.Assert lng1 = 2
    Debug.Assert str1suf = "x"

    AnaStr "-2x", lng1, str1suf
    Debug.Assert lng1 = -2
    Debug.Assert str1suf = "x"

    AnaStr "-2x^2", lng1, str1suf
    Debug.Assert lng1 = -2
    Debug.Assert str1suf = "x^2"
    
    AnaStr "x^2", lng1, str1suf
    Debug.Assert lng1 = 1
    Debug.Assert str1suf = "x^2"

    AnaStr "-x^2", lng1, str1suf
    Debug.Assert lng1 = -1
    Debug.Assert str1suf = "x^2"

End Sub