Dynamic LCA

This repo contains a partial implementation of Gabow's data structure for the dynamic lowest common ancestor (LCA) problem. Specifically, it contains code for a data structure that supports

• O(1) worse-case LCA queries
• O(log n) amortized insertion of leaves

See writeup.pdf for more details (including performance analysis).

File Structure

• lcaTree.hpp/cpp: Defines the class ExpensiveTreeNode, which supports O(1) LCA queries and O(log^2 n) amortized insertion of leaves
• lcaMultilevel.hpp/cpp: Defines the class MultilevelTreeNode, which uses indirection to support O(1) LCA queries and O(log n) amortized insertion of leaves
• demo.cpp: A minimal example demonstrating how to construct a tree and run LCA queries on it
• test.cpp: Tests correctness of the LCA implementation
• timingTest.cpp: Tests efficiency of the LCA implementation
• generateRandTree.hpp/cpp: Defines a suite of functions used to generate random trees for testing