按标识符字符串从列表中删除重复元素(C#)

using System;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        List<string> identifiers = new List<string>()
        {
            "apple",
            "banana",
            "apple",
            "orange",
            "banana"
        };

        HashSet<string> uniqueIdentifiers = new HashSet<string>();

        for (int i = 0; i < identifiers.Count; i++)
        {
            if (!uniqueIdentifiers.Contains(identifiers[i]))
            {
                uniqueIdentifiers.Add(identifiers[i]);
            }
            else
            {
                identifiers.RemoveAt(i);
                i--;
            }
        }

        foreach (string identifier in identifiers)
        {
            Console.WriteLine(identifier);
        }
    }
}

apple
banana
orange