c#一个含有字符串的数组，例如:["a","b","a","c","b","d","a"],需要得到一个新数组 ["a1","b1","a2","c","b2","d","a3"] 要求: 未重复的元素不处理 重复的元素加上编号 不能影响正常数组的顺序

在C#中，你可以使用`LINQ`（Language Integrated Query）和`HashSet`来实现这个需求。首先，你需要创建一个`HashSet`来跟踪已经处理过的字符串，然后遍历原始数组，对于每个重复的字符串，就在后面添加一个编号。以下是代码示例：

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        string[] inputArray = {"a", "b", "a", "c", "b", "d", "a"};
        string[] result = ProcessDuplicates(inputArray);
        foreach (string item in result)
        {
            Console.WriteLine(item);
        }
    }

    static string[] ProcessDuplicates(string[] array)
    {
        HashSet<string> processedStrings = new HashSet<string>();
        Dictionary<string, int> duplicateCount = new Dictionary<string, int>();

        // 创建结果数组
        List<string> resultList = new List<string>();

        for (int i = 0; i < array.Length; i++)
        {
            if (!processedStrings.Contains(array[i]))
            {
                resultList.Add(array[i]);
                processedStrings.Add(array[i]);
            }
            else
            {
                string key = array[i];
                if (!duplicateCount.ContainsKey(key))
                {
                    duplicateCount[key] = 1;
                    resultList.Add($"{key}{duplicateCount[key]}");
                }
                else
                {
                    duplicateCount[key]++;
                    resultList.Add($"{key}{duplicateCount[key]}");
                }
            }
        }

        return resultList.ToArray(); // 返回新的字符串数组
    }
}

运行这段代码后，你会得到预期的结果：`["a", "b", "a1", "c", "b1", "d", "a2"]`。