A lot depends on what you're trying to do. If you intend on populating once, then searching multiple times, I'd use a hash. If you intend on doing other stuff, I might be less inclined to search as much. What else do you do with this thing?

A good rule of thumb is that your needs drive the data structure. In all but the most pathologically simple tasks, there is more than one data structure that can be used. Just because you chose array first doesn't mean that array should be used now, especially if the program has changed to meet changing requirements.

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We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.