I have noticed that different data structures are used when we implement search algorithms. For example, we use queues to implement breadth first search, stacks to implement depth-first search and min-heaps to implement the A* algorithm. In these cases, we do not need to construct the search tree explicitly.
But I can not find a simple data structure to simulate the searching process of the AO* algorithm. I would like to know if constructing the search tree explicitly is the only way to implement AO* algorithm? Can anybody provide me an efficient implementation?