How to quickly search in c# for an array of strings?

Question

C++ / C#

Now I am looking for an occurrence of an array of strings in the line line s

string[] s = { "тест1","тест2","тест3","тест4" };

for (int j = 0; j < s.Length; j++)
{
  if (line.IndexOf(s[j]) > 0)
  {

  }
}

How can you search even faster than this code?

Answer 1

I didn't find the exact information, but it seems that string.IndexOf uses the simplest substring search algorithm, which runs in O(nm). (n is the length of the original string, m is the length of the sample).
And since you have p more samples, we get cubic complexity.
The easiest option in this case is to use a different substring search algorithm. In general, there are a lot of substring search algorithms. Different algorithms with the same asymptotics can manifest themselves very differently on different data. In any case, it is worth trying different options to determine which algorithm will be faster in your case.
But, at first glance, it seems to me that the Aho-Korasik algorithm is quite suitable for you.

Answer 2

I apologize for necroposting, but there is a much simpler solution than Aho-Korashiki =)

string[] array = { "тест1", "тест2", "тест3", "тест4" };

if (new Regex(string.Join("|", array.Select(Regex.Escape))).IsMatch(line))
{
    // do work
}