Verified Root-Balanced Trees

نویسنده

  • Tobias Nipkow
چکیده

Andersson introduced general balanced trees, search trees based on the design principle of partial rebuilding: perform update operations naively until the tree becomes too unbalanced, at which point a whole subtree is rebalanced. We define and analyze a functional version of general balanced trees which we call root-balanced trees. Using a lightweight model of execution time, amortized logarithmic complexity is verified in the theorem prover Isabelle. Experimental results show competitiveness of root-balanced with AVL and red-black trees.

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Root-Balanced Tree

Andersson [1, 2] introduced general balanced trees, search trees based on the design principle of partial rebuilding: perform update operations naively until the tree becomes too unbalanced, at which point a whole subtree is rebalanced. This article defines and analyzes a functional version of general balanced trees, which we call root-balanced trees. Using a lightweight model of execution time...

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تاریخ انتشار 2017