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removes move field from UCTNode #2

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removes move field from UCTNode #2

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18 changes: 11 additions & 7 deletions search/uct.py
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Original file line number Diff line number Diff line change
Expand Up @@ -9,9 +9,8 @@
FPU_ROOT = 0.0

class UCTNode():
def __init__(self, board=None, parent=None, move=None, prior=0):
def __init__(self, board=None, parent=None, prior=0):
self.board = board
self.move = move
self.is_expanded = False
self.parent = parent # Optional[UCTNode]
self.children = OrderedDict() # Dict[move, UCTNode]
Expand All @@ -32,14 +31,19 @@ def U(self): # returns float
def best_child(self, C):
return max(self.children.values(),
key=lambda node: node.Q() + C*node.U())

def best_move_and_child(self, C):
return max(self.children.items(),
key=lambda move, node: node.Q() + C*node.U())

def select_leaf(self, C):
current = self
move = None
while current.is_expanded and current.children:
current = current.best_child(C)
move, current = current.best_move_and_child(C)
if not current.board:
current.board = current.parent.board.copy()
current.board.push_uci(current.move)
current.board.push_uci(move)
return current

def expand(self, child_priors):
Expand All @@ -48,7 +52,7 @@ def expand(self, child_priors):
self.add_child(move, prior)

def add_child(self, move, prior):
self.children[move] = UCTNode(parent=self, move=move, prior=prior)
self.children[move] = UCTNode(parent=self, prior=prior)

def backup(self, value_estimate: float):
current = self
Expand Down Expand Up @@ -87,8 +91,8 @@ def UCT_search(board, num_reads, net=None, C=1.0, verbose=False, max_time=None,
bestmove, node = max(root.children.items(), key=lambda item: (item[1].number_visits, item[1].Q()))
score = int(round(cp(node.Q()),0))
if send != None:
for nd in sorted(root.children.items(), key= lambda item: item[1].number_visits):
send("info string {} {} \t(P: {}%) \t(Q: {})".format(nd[1].move, nd[1].number_visits, round(nd[1].prior*100,2), round(nd[1].Q(), 5)))
for nd in sorted(root.children.items(), key= lambda move, item: item[1].number_visits):
send("info string {} {} \t(P: {}%) \t(Q: {})".format(nd[0], nd[1].number_visits, round(nd[1].prior*100,2), round(nd[1].Q(), 5)))
send("info depth 1 seldepth 1 score cp {} nodes {} nps {} pv {}".format(score, count, int(round(count/delta, 0)), bestmove))

# if we have a bad score, go for a draw
Expand Down