توضیح شبه کد مربوط به حل پازل 8 با استفاده از A*

سلام.

این شبه کد مربوط میشه به حل معمای 8 (پازل 8) با استفاده از روش A-Star.

ولی برام نامفهومه، خوده تعریف a-star رو متوجه شدم، ولی این شبه کد رو خوب متوجه نمیشم.
اگر برام توضیحش بدید واقعا ممنون میشم.

function A*(start,goal)

     closedset := the empty set                 % The set of nodes already evaluated.     

     openset := set containing the initial node % The set of tentative nodes to be evaluated.

     g_score[start] := 0                        % Distance from start along optimal path.

     h_score[start] := heuristic_estimate_of_distance(start, goal)

     f_score[start] := h_score[start]           % Estimate d total distance from start to goal through y.

     while openset is not empty

         x := the node in openset having the lowest f_score[] value

         if x = goal

             return reconstruct_path(came_from,goal)

         remove x from openset

         add x to closedset

         foreach y in neighbor_nodes(x)

             if y in closedset

                 continue

             tentative_g_score := g_score[x] + dist_between(x,y)

 

             if y not in openset

                 add y to openset

 

                 tentative_is_better := true

             elseif tentative_g_score < g_score[y]

                 tentative_is_better := true

             else

                 tentative_is_better := false

             if tentative_is_better = true

                 came_from[y] := x

                 g_score[y] := tentative_g_score

                 h_score[y] := heuristic_estimate_of_distance(y, goal)

                 f_score[y] := g_score[y] + h_score[y]

     return failure

 

 function reconstruct_path(came_from,current_node)

     if came_from[current_node] is set

         p = reconstruct_path(came_from,came_from[current_node])

         return (p + current_node)

     else         return the empty path