计算字符串中两个字符的总对数

Question

基本上我需要计算一个字符串中的总体数量,这是为了显示一些信息,比如在一个RegularExpression应用程序中建议打开的子标记表达式的总数.

然后我需要计算关闭的"()"的总数,而不是"("和"总数")的总和.

例如在这个字符串中:

Hello (world)

预期结果将是:1关闭

这里:

Hello (world) ((how are (you)?

预期结果将是:2关闭,2打开

和这里:

Hello ) ( World?

预期结果将是:2开放

只是请求可以给我一些想法,哪些可以改进计算方法？

我得到了"("和")"字符的总数,现在我不知道该怎么办.

更新:

我用这个字符串示例测试:

(((X)))

但我得到4个未闭合,只有1个关闭,我正在使用此代码:

Public Function Replace_All_Characters_Except(ByVal str As String, _
                                              ByVal chars As Char(), _
                                              replaceWith As Char) As String

    Dim temp_str As String = String.Empty

    For Each c As Char In str
        For Each cc As Char In chars
            If c = cc Then temp_str &= cc
        Next cc
    Next c

    Return temp_str

End Function

    Dim Total_Parentheses As String = Replace_All_Characters_Except(TextBox_RegEx.Text, {"(", ")"}, String.Empty)
    Dim Total_Unagrupated As Integer = Total_Parentheses.Replace("()", String.Empty).Length
    Dim Total_Agrupated As Integer = (Total_Parentheses.Length - Total_Unagrupated) \ 2

    MsgBox(Total_Parentheses)
    MsgBox(Total_Unagrupated)
    MsgBox(Total_Agrupated)

Answer 1

我会在这里使用Stack

Stack<char> stack = new Stack<char>();
string input = @"Hello (world) ((how are (you)?";
//string input = "Hello ) ( World?";

int closed = 0;
int opened = 0;

foreach (var ch in input)
{
    if (ch == '(')
        stack.Push('#');
    else if (ch == ')')
    {
        if (stack.Count == 0)
            opened++;
        else
        {
            closed++;
            stack.Pop();
        }
    }
}

opened += stack.Count;

Console.WriteLine("Opened:{0} Closed:{1}", opened, closed);

编辑

    Dim stack As New Stack(Of Char)
    Dim input As String = "Hello (world) ((how are (you)?"
    'Dim input As String = "Hello ) ( World?"

    Dim opened As Integer = 0
    Dim closed As Integer = 0

    For Each ch As Char In input
        If ch = "(" Then
            stack.Push("#")
        ElseIf ch = ")" Then
            If stack.Count = 0 Then
                opened = opened + 1
            Else
                closed = closed + 1
                stack.Pop()
            End If
        End If
    Next

    opened = opened + stack.Count

    Console.WriteLine("Opened:{0} Closed:{1}", opened, closed)