Index mapping

Not to be confused with Index map, a finding aid in cartography.

Index mapping (or direct addressing, or a trivial hash function) in computer science describes using an array, in which each position corresponds to a key in the universe of possible values.[1] The technique is most effective when the universe of keys is reasonably small, such that allocating an array with one position for every possible key is affordable. Its effectiveness comes from the fact that an arbitrary position in an array can be examined in constant time.

  1. ^ Cormen, Thomas H. (2009). Introduction to algorithms (3rd ed.). Cambridge, Mass.: MIT Press. pp. 253–255. ISBN 9780262033848. Retrieved 26 November 2015.