- let color = get_color (get_turn state) in

- let moves a = List.map (fun b -> (a, b)) (free_neighbors state a) in

- List.flatten (List.map moves (movables state color))

- let color = get_color (get_turn state) in

- let flies a = List.map (fun b -> (a, b)) (free_dots state) in

- List.flatten (List.map flies (movables state color))

- | Put of int (* index *)

- | Move of int * int (* from, goal *)

- | Fly of int * int (* from, goal *)

- | Capture of int (* optional capture index *)

-let string_of_move = function

- | Put i -> Printf.sprintf "put %d" i

- | Move (f, g) -> Printf.sprintf "move %d %d" f g

- | Fly (f, g) -> Printf.sprintf "fly %d %d" f g

- | Capture i -> Printf.sprintf "capture %d" i

-type node = Node of state * move * node list (* state, move, children *)

-let string_of_node = function

- | Node (_, move, _) -> "Node(_, " ^ (string_of_move move) ^ ", _)"

-let can_capture state move = match move with

- | Put i -> in_mill state i

- | Move (from, goal) -> in_mill state goal

- | Fly (from, goal) -> in_mill state goal

-let rec build state last_move depth =

- build s (Put i) (pred depth)

- let children = List.map aux (free_dots state) in

- Node (state, last_move, children)

- build s (Fly (from, goal)) (pred depth)

- let children = List.map aux (all_flies state) in

- Node (state, last_move, children)

- build s (Move (from, goal)) (pred depth)

- let children = List.map aux (all_moves state) in

- Node (state, last_move, children)

- build s (Capture i) (pred depth)

- let opponent = get_color (succ (get_turn state)) in

- let children = List.map aux (capturables state opponent) in

- Node (state, last_move, children)

- if can_capture state last_move then build_capture ()

- else if depth <= 0 then Node (state, last_move, [])

- else if can_put state then build_put ()

- else if can_fly state then build_fly ()

- if depth > 0 then (Printf.printf "+"; indent (pred depth))

- let rec p depth = function

- Node (state, move, list) ->

- Printf.printf "%s\n" (string_of_move move);

- List.iter (p (succ depth)) list

-let count_positions node =

- let rec count node = match node with

- | Node (_, _, children) ->

- let counts = List.map count children in

- List.fold_left (+) 0 counts

-let rec score heuristic node =

- let scores = List.map (score heuristic) lst in

- List.fold_left max min_int scores

- let scores = List.map (score heuristic) lst in

- List.fold_left min max_int scores

- | Node (s, move, []) -> heuristic s

- | Node (s, move, children) ->

- if (get_turn s) mod 2 = 1 then max_score children

- else min_score children

-let estimate_basic state =

- let black = (get_count state Black)

- and white = (get_count state White) in

-let estimate_mc playouts state = Ai_montecarlo.estimate state 0 playouts 30

-let estimate_hybrid playouts state =

- let e = estimate_basic state in

- (max 100 (playouts/2)) * e + estimate_mc playouts state

- let find_best state lastmove depth playouts =

- let root = build state lastmove depth in

- let positions = count_positions root in

- let nplayouts = playouts / positions in

- let children = match root with Node (_, _, c) -> c in

- let scores = List.map (score (estimate_hybrid nplayouts)) children in

- let better = if (get_turn state) mod 2 = 0 then (<) else (>) in

- let init = if (get_turn state) mod 2 = 0 then max_int else min_int in

- let rec select nodes scores selected score =

- if nodes = [] then selected

- let n, s = (List.hd nodes), (List.hd scores) in

- if better s score then select (List.tl nodes) (List.tl scores) n s

- else select (List.tl nodes) (List.tl scores) selected score

- select children scores (Node (state, lastmove, [])) init

- val mutable last_move = Init

- let selected = find_best state Init 2 15000 in

- | Node(_, Put i, _) -> last_move <- Put i ; i

- | _ -> failwith "no put found"

- let selected = find_best state Init 4 30000 in

- | Node(_, Move (f, g), _) -> last_move <- Move (f, g) ; f, g

- | _ -> failwith "no move found"

- let selected = find_best state Init 3 30000 in

- | Node(_, Fly (f, g), _) -> last_move <- Fly (f, g) ; f, g

- | _ -> failwith "no fly found"

- end_of_turn state; (* unrolled later *)

- let selected = find_best state last_move 2 10000 in

- | Node(_, Capture i, _) -> last_move <- Capture i ; i

- | _ -> failwith "no capture found"