Navigating Central Path with Electrical Flows: from Flows to Matchings, and Back
arXiv:1307.2205
Abstract
We present an -time algorithm for the maximum s-t flow and the minimum s-t cut problems in directed graphs with unit capacities. This is the first improvement over the sparse-graph case of the long-standing time bound due to Even and Tarjan [EvenT75]. By well-known reductions, this also establishes an -time algorithm for the maximum-cardinality bipartite matching problem. That, in turn, gives an improvement over the celebrated celebrated time bound of Hopcroft and Karp [HK73] whenever the input graph is sufficiently sparse.