Question

I have a sorted StringList and wanted to replace

foreach (string line3 in CardBase.cardList)
            if (line3.ToLower().IndexOf((cardName + Config.EditionShortToLong(edition)).ToLower()) >= 0)
            {
                return true;
            }

with a binarySearch, since the cardList ist rather large(~18k) and this search takes up around 80% of the time.

So I found the List.BinarySearch-Methode, but my problem is that the lines in the cardList look like this:

Brindle_Boar_(Magic_2012).c1p247924.prod

But I have no way to generate the c1p… , which is a problem cause the List.BinarySearch only finds exact matches.

How do I modify List.BinarySearch so that it finds a match if only a part of the string matches?

e. g.
searching for Brindle_Boar_(Magic_2012) should return the position of Brindle_Boar_(Magic_2012).c1p247924.prod

Answer 1

List.BinarySearch will return the ones complement of the index of the next item larger than the request if an exact match is not found.

So, you can do it like this (assuming you’ll never get an exact match):

var key = (cardName + Config.EditionShortToLong(edition)).ToLower();
var list = CardBase.cardList;

var index = ~list.BinarySearch(key);
return index != list.Count && list[index].StartsWith(key);