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Oh, in that case, if you are capable of going to a University's library and look for a book called Introducion to Algorithms by Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford...

Well, measuring the usefulness of data structures, you use the big O notation.

Things like quadratic search has a big O notation of O(n^2), a binary search is O(n log n) (methinks...), and so on....