xTrek: An Influence-Aware Technique for Dijkstra’s and A Pathfinders

Finding a path (in black) from the top-left node to the bottom-right node of a 50 × 50 grid using the risk-adverse algorithm (RAP): (a) without attractors and repulsors, the search space only covers neutral nodes (in cyan) along or close to the path (in black); (b) with 2 attractors, the search space reduces itself to neutral nodes (in cyan) and influence-constant attractor nodes (in red blended with cyan) found on the way to the goal node; (c) with 2 repulsors, the search space covers neutral nodes (in cyan) found on the way to the goal node, but influence-constant repulsor nodes (in light lilac) repel the search; (d) with 2 attractors and 2 repulsors, the search space covers neutral nodes (in cyan) and influence-constant attractor nodes (in red blended with cyan) but not repulsor nodes (in light lilac). Nodes in cyan or blended with cyan represent visited nodes, that is, open and closed nodes.