CODEWITHSUNDEEP
javasearchcollectionshashmapprocessing-efficiency
codeninja
codeninja

Reputation: 19

Simple Collection With String Objects which allows search in 0(1) operation

I have simple collection of string objects might be around 10 elements , but i use this collection in production environment such that the we search for a given string in that collection millions of tiimes , what is the best collection or data structure we can use to get the best results so that seach operation can be performed in 0(1) time we can use HashMap here but the order of search there is in constant time not 0(1) i want to make sure that search is 0(1).

Our data structure must return true if present , else false if not present

Upvotes: 0

Views: 821

Answers (3)

Louis Wasserman
Louis Wasserman

Reputation: 198221

Constant time is O(1). HashMap is fine. (Or HashSet, depending on whether you need a Set or a Map.)

If your set is immutable, Guava's ImmutableSet will reduce memory footprint by a factor of ~3 (and probably give you a small constant factor of improved speed).

Upvotes: 1

texclayton
texclayton

Reputation: 189

If you can't use HashSet/HashMap as previously suggested, you could write a Radix Tree implementation.

Upvotes: 0

Andreas Dolk
Andreas Dolk

Reputation: 114807

Use a HashSet<String> structure. The contains() operation has a complexity of O(1).

Upvotes: 5

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