字符串处理问题，带佬进！

Question

现有需要处理一个字符串如下:
2(1A1B)2(1B1A)2(1A1C)
要求输出:
6A4B2C=12
如题,有何最优解

Answer 1

以下是一个正则表达式实现的代码示例：

using System.Text.RegularExpressions;

var inputString = "2(1A1B)2(1B1A)2(1A1C)";
var outputString = ProcessString(inputString);
Console.WriteLine(outputString);
Console.ReadKey();
static string ProcessString(string inputString)
{
    // 使用正则表达式匹配括号内的内容
    var pattern = @"(\d+)\((\d+[A-Z]+\d+[A-Z]+)\)";
    var outputString = Regex.Replace(inputString, pattern, m =>
    {
        var count = int.Parse(m.Groups[1].Value);
        var content = m.Groups[2].Value;
        return MultiplyString(content, count);
    });

    // 统计字符出现的次数
    var charCount = new Dictionary<char, int>();
    foreach (var c in outputString.Where(char.IsLetter))
    {
        if (charCount.ContainsKey(c))
        {
            charCount[c]++;
        }
        else
        {
            charCount[c] = 1;
        }
    }

    // 构建最终的输出结果
    var finalResult = charCount.Aggregate("", (current, entry) => current + (entry.Value.ToString() + entry.Key));
    finalResult += "=" + charCount.Sum(x => x.Value);

    return finalResult;
}

static string MultiplyString(string inputString, int count)
{
    var result = "";
    for (var i = 0; i < count; i++)
    {
        result += inputString;
    }
    return result;
}

输出结果：

6A4B2C=12