RAM Complexity is Optimal
نویسندگان
چکیده
We show that the programs of any classical (as opposed to parallel or interactive) computation model or programming language that satisfies natural postulates of effectiveness (which specialize Gurevich’s Sequential Postulates) can be simulated by a random access machine (RAM) with only constant overhead. In essence, the effectiveness postulates assert the following: states can be represented as logical structures; transitions depend on a fixed finite set of terms (those referred to in the algorithm); basic operations can be programmed from constructors; and transitions commute with isomorphisms. Complexity for any domain is measured in terms of constructor operations. It follows that algorithmic lower bounds for the RAM model hold (up to a constant factor) for any and all effective classical models of computation, whatever its control structures and data structures.
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