Core Concepts
An efficient exact algorithm for finding optimal burning sequences that minimize the time required to propagate influence over an entire social network represented as a graph.
Abstract
The paper proposes an exact algorithm, called PRYM, for solving the Graph Burning Problem (GBP), which models the spread of influence on social networks. The GBP is an NP-hard optimization problem that seeks to find a sequence of vertices (a burning sequence) that minimizes the time required to burn the entire graph.
The key contributions of the paper are:
PRYM formulates the GBP as an integer programming (IP) model and employs a row generation approach to efficiently solve the problem. This allows PRYM to find provably optimal solutions significantly faster than the previously best known exact algorithm, GDCA.
PRYM is able to solve real-world instances with up to 200,000 vertices in less than 35 seconds, increasing the size of graphs for which optimal solutions are known by a factor of 14 compared to GDCA.
The row generation approach in PRYM exploits the observation that a very small number of covering constraints (often just dozens) are often sufficient to prove the feasibility or infeasibility of the IP model for a given burning sequence length. This leads to substantial improvements in running time and memory usage compared to previous methods.
The paper demonstrates the effectiveness of PRYM through extensive computational experiments on a large benchmark of real-world network instances. The results show that PRYM outperforms the state-of-the-art GDCA algorithm by a significant margin, both in terms of running time and the size of instances that can be solved optimally.
Stats
The burning number of the ia-enron-only graph is 4.
The burning number of the DD244 graph is 7.
The burning number of the ca-netscience graph is 6.
Quotes
"Our algorithm, however, solves real-world instances with almost 200,000 vertices in less than 35 seconds, increasing the size of graphs for which optimal solutions are known by a factor of 14."
"To date, the most efficient exact algorithm for the GBP, denoted here by GDCA, is able to obtain optimal solutions for graphs with up to 14,000 vertices within two hours of execution. In comparison, our algorithm finds provably optimal solutions approximately 236 times faster, on average, than GDCA."