c# - 计算字符串中的开始和结束字符对？

Question

假设我有字符串:

You are pretty <lady> but that <girl> is prettier <than> you.

抱歉是英文，但我怎么能数出上面的文本中有多少 <> 呢？

我知道我能做到:

int count = message.Length - message.Replace("<", "").Replace(">", "").Length;

但即使文本是这样的，这也算数:

Hey <<<< you <<<<< how you doing >>>

事实上，我只想计算 <> 的对数，因此当它找到开始 < 和结束 > 时计数会加一，并且应该只在找到 < 时才开始计数。

Answer 1

这样怎么样。基本上，如果您之前曾遇到过 <，您应​​该只计算 >。或者换个说法。将 < 堆叠起来，然后在遇到 > 时分别使用其中一个。

string test = "You are pretty <lady> but that <girl> is prettier <than> you.";

int startcount = 0;
int paircount = 0;
foreach( char c in test ){
  if( c == '<' )
    startcount++;
  if( c == '>' && startcount > 0 ){
    startcount--;
    paircount++;
  }
}
//paircount should now be the value you are after.

编辑

我认为 <<<>>> 应该算作 3 而不是 1，所以您需要在上面进行快速修复。要将 <<<>>> 计为仅 1，请更改为此

string test = "You are pretty <lady> but that <girl> is prettier <than> you.";

bool foundstart = false;
int paircount = 0;
foreach( char c in test ){
  if( c == '<' )
    foundstart = true;
  if( c == '>' && foundstart ){
    foundstart = false;
    paircount++;
  }
}
//paircount should now be the value you are after.