从列表中删除具有优先级的项目

Question

Lets suppose i have a list and i want to remove accoding to the condition that if priority item is there then remove all smaller priority items. for eg

Sortedarr[] =["world champion","Best performer","Best gold", "Best silver", "Best bronze", "regional"]

Conditions.

1. if gold is present i want every medal except silver and bronze.
2. if gold is not presnt but max silver is present then show only silver not bronze
3. if both silver and gold are not present then show bronze.

the array would always be sorted so always gold>siilver>bronze would be the order.

My implementation is working but i dont think its the optimised way of doing it.

    if(arr.Contains("Best gold")){
                sortedArr.RemoveAll(x => ((string)x) == "Best silver" 
                 || ((string)x) == "Best Bronze" );
            }
    if (sortedArr.Contains("Best silver")) {
                sortedArr.RemoveAll(x =>((string)x) == "Best bronze");
            }
         

thank you in advance

Answer 1

Your question is not clear. but you can use Array.IndexOf Method to check item is present:

List<string> array =(new string[] {"world champion", "Best performer", "Best gold", "Best silver", "Best bronze", "regional"}).ToList();

if (array.IndexOf("Best gold") > 0) 
    array.RemoveAll(m=>m.Contains("Best silver") || m.Contains("Best bronze"));

else if (array.IndexOf("Best silver") > 0)
    array.RemoveAll(m => m.Contains("Best bronze"));

Answer 2

List<string> array =(new string[] {"world champion", "Best performer", "Best gold", "Best silver", "Best bronze", "regional"});

    array.Contains("Best gold")  ? array.RemoveAll(x => ((string)x) == "Best silver" || ((string)x) == "Best Bronze" ) 
                                 : (array.Contains("Best silver") ?
                                  array.RemoveAll(x =>((string)x) == "Best bronze")
                                 : return array)
                         

Answer 3

If it comes to sorting, I would recommend implementing own comparer for string, so implementing interface IComparer<string> .

Below simply checks wether compared string contains either gold, silver or bronze and gives desired output based on score of a medal.

In case of a tie, we fallback to chosen comparer, here StringComparer.OrdinalIgnoreCase .

In case if none of the compared strings contain any of a medals, then we also fallback to chosen comparison type.

public class MedalComparer : IComparer<string>
{
    private const string Gold = "gold";
    private const string Silver = "silver";
    private const string Bronze = "bronze";
    // Here you should put all medals with respctive score
    private static readonly Dictionary<int, string> Medals = new()
    {
        {1, Gold}, {2, Silver}, {3, Bronze},
    };

    private static readonly StringComparison StringComparison = StringComparison.OrdinalIgnoreCase;
    private static readonly IComparer<string> _fallbackComparer = StringComparer.OrdinalIgnoreCase;

    public int Compare(string x, string y)
    {
        return IsTie(x, y)
            ? _fallbackComparer.Compare(x, y)
            : Evaluate(x, y) ?? _fallbackComparer.Compare(x, y);
    }

    private static bool IsTie(string x, string y)
    {
        return (x.Contains(Gold, StringComparison) && y.Contains(Gold, StringComparison)) ||
            (x.Contains(Silver, StringComparison) && y.Contains(Silver, StringComparison)) ||
            (x.Contains(Bronze, StringComparison) && y.Contains(Bronze, StringComparison));
    }

    private static int? Evaluate(string x, string y)
    {
        foreach (var medalKey in Medals.Keys.OrderBy(x => x))
        {
            if(x.Contains(Medals[medalKey], StringComparison))
            {
                return 1;
            }

            if (y.Contains(Medals[medalKey], StringComparison))
            {
                return -1;
            }
        }

        return null;
    }
}

Then you can pass it conveniently to OrderBy method as shown below:

public static class Program
{
    public static async Task Main(string[] args)
    {
        var testData = new[]{ "world champion","Best performer","Best gold", "Best silver", "Best bronze", "regional"};

        var sorted = testData.OrderBy(x => x, new MedalComparer());
    }
}