Matching triangles and basing hardness on an extremely popular conjecture
Due to the lack of unconditional polynomial lower bounds, it is now in fashion to prove
conditional lower bounds in order to advance our understanding of the class P. The vast …
conditional lower bounds in order to advance our understanding of the class P. The vast …
Imposing contiguity constraints in political districting models
Beginning in the 1960s, techniques from operations research began to be used to generate
political districting plans. A classical example is the integer programming model of Hess et …
political districting plans. A classical example is the integer programming model of Hess et …
Multiple-source multiple-sink maximum flow in directed planar graphs in near-linear time
We give an O(n\log^3n) algorithm that, given an n-node directed planar graph with arc
capacities, a set of source nodes, and a set of sink nodes finds a maximum flow from the …
capacities, a set of source nodes, and a set of sink nodes finds a maximum flow from the …
Subcubic algorithms for Gomory–Hu tree in unweighted graphs
Every undirected graph G has a (weighted) cut-equivalent tree T, commonly named after
Gomory and Hu who discovered it in 1961. Both T and G have the same node set, and for …
Gomory and Hu who discovered it in 1961. Both T and G have the same node set, and for …
Popular conjectures as a barrier for dynamic planar graph algorithms
The dynamic shortest paths problem on planar graphs asks us to preprocess a planar graph
G such that we may support insertions and deletions of edges in G as well as distance …
G such that we may support insertions and deletions of edges in G as well as distance …
Political districting to minimize cut edges
When constructing political districting plans, prominent criteria include population balance,
contiguity, and compactness. The compactness of a districting plan, which is often judged by …
contiguity, and compactness. The compactness of a districting plan, which is often judged by …
Structured recursive separator decompositions for planar graphs in linear time
Given a triangulated planar graph G on n vertices and an integer r< n, an r--division of G with
few holes is a decomposition of G into O (n/r) regions of size at most r such that each region …
few holes is a decomposition of G into O (n/r) regions of size at most r such that each region …
Cut-equivalent trees are optimal for min-cut queries
Min-Cut queries are fundamental: Preprocess an undirected edge-weighted graph, to
quickly report a minimum-weight cut that separates a query pair of nodes s, t. The best data …
quickly report a minimum-weight cut that separates a query pair of nodes s, t. The best data …
New algorithms and lower bounds for all-pairs max-flow in undirected graphs
We investigate the time-complexity of the All-Pairs Max-Flow problem: Given a graph with n
nodes and m edges, compute for all pairs of nodes the maximum-flow value between them …
nodes and m edges, compute for all pairs of nodes the maximum-flow value between them …
Faster algorithms for all-pairs bounded min-cuts
The All-Pairs Min-Cut problem (aka All-Pairs Max-Flow) asks to compute a minimum $ s $-$ t
$ cut (or just its value) for all pairs of vertices $ s, t $. We study this problem in directed …
$ cut (or just its value) for all pairs of vertices $ s, t $. We study this problem in directed …