On-line strategies for evacuating from an unknown grid network area in the plane by groups

This paper focuses on studying the online strategies of evacuating problems in a gird network. First, we proved that the double strategy can work well for solving the single source point evacuating problem in the grid network, even the boundary of the affected area is a concave polygon, and proposed a 24-competitive evacuating strategy for the evacuating problem by two groups. Then, we studied the multi-source points evacuating problems, and proposed respectively a 24-competitive evacuation strategy for 2-source points and a 16-competitive evacuation strategy for 4-source points to solve the evacuating problems in the grid network.