Introduction - If you have any usage issues, please Google them yourself
A* algorithm is a heuristic search. It extended node in the order of priority similar to the breadth of search, but in every generation is a sub-node calculated valuation function F, to estimate initial node to the node, the price and it arrived at the target node, and the price; Whenever expansion node, the question has always extended to all nodes with the smallest choosing F value of the node as expansion targets, in order to search as far as possible along the most promising direction.