I am trying to write a kind of simple search engine. I have a determined number of main subjects that are associated with specific keywords. The aim is to recognize the main subject from an input partial keyword. I am thinking of using a : Dictionary<string, List<string>>. I'll have to search in this dictionary and find, e.g., all keywords beginning with a 3 characters string and their main subject which is associated.
Is my solution the best one ? And how can I efficiently look through those data without having to check manually every List, string by string.
Let my know if I'am not clear.
You're looking for Trie data structure, it is the recommended way of doing starts with search. Here is a blog post talking about it. You can find the source here.
Here's how use the above implementation, code from the above article.
//Create trie
Trie < string > trie = new Trie < string > ();
//Add some key-value pairs to the trie
trie.Put("James", "112");
trie.Put("Jake", "222");
trie.Put("Fred", "326");
//Search the trie
trie.Matcher.NextMatch('J'); //Prefix thus far: "J"
trie.Matcher.GetPrefixMatches(); //[112, 222]
trie.Matcher.IsExactMatch(); //false
trie.Matcher.NextMatch('a');
trie.Matcher.NextMatch('m'); //Prefix thus far: "Jam"
trie.Matcher.GetPrefixMatches(); //[112]
trie.Matcher.NextMatch('e');
trie.Matcher.NextMatch('s'); //Prefix thus far: "James"
trie.Matcher.IsExactMatch(); //true
trie.Matcher.GetExactMatch(); //112
//Remove a string-value pair
trie.Remove("James");