这两段alpha-beta 剪枝算法python代码的实现效果为什么会不同
这段是正常的
def alphbetaSearch(board):
global num
a = actions(board)
judge_for_player = player(board)
if judge_for_player is X:
v = float('-inf')
for move in a:
result_board = result(board, move)
v_every = min_value_ab(result_board, float('-inf'), float('inf'))
if v <= v_every:
v = v_every
marks = move
print(marks, v,num)
else:
v = float('inf')
for move in a:
result_board = result(board, move)
v_every = max_value_ab(result_board, float('-inf'), float('inf'))
if v >= v_every:
v = v_every
marks = move
print(marks, v,num)
return marks
def max_value_ab(board, alpha, beta):
global num
num=num+1
if terminal(board):
return utility(board)
v = float('-inf')
for move in actions(board):
result_board = result(board, move)
v_every = min_value_ab(result_board, alpha, beta)
v = max(v, v_every)
if v >= beta: # alpha-beta pruning
return v
alpha = max(alpha, v)
return v
def min_value_ab(board, alpha, beta):
global num
num=num+1
if terminal(board):
return utility(board)
v = float('inf')
for move in actions(board):
result_board = result(board, move)
v_every = max_value_ab(result_board, alpha, beta)
v = min(v, v_every)
if v <= alpha: # alpha-beta pruning
return v
beta = min(beta, v)
return v
这段是有问题的，不能正确求出最优解
def alphbetaSearch(board):
global num
a = actions(board)
v11 = float('-inf')
v12 = float('inf')
judge_for_player = player(board)
if judge_for_player is X:
for i11 in a:
v1_every = min_value_ab(result(board, i11), v11, v12)
if v11 <= v1_every:
v11 = v1_every
marks = i11
print(num)
else:
for i12 in a:
v2_every = max_value_ab(result(board, i12), v11, v12)
if v12 >= v2_every:
v12 = v2_every
marks = i12
print(num)
return marks
def max_value_ab(board, alph, beta):
global num
num=num+1
if terminal(board):
return utility(board)
v2 = float('-inf')
for i2 in actions(board):
result_board = result(board, i2)
v_every = min_value_ab(result_board, alph, beta)
v2 = max(v2, v_every)
if v2 >= beta: # alpha-beta pruning
return v2
alph = max(alph, v2)
return v2
def min_value_ab(board, alph, beta):
global num
num=num+1
if terminal(board):
return utility(board)
v3 = float('inf')
for i3 in actions(board):
result_board = result(board, i3)
v_every = min_value_ab(result_board, alph, beta)
v3 = max(v3, v_every)
if v3 >= beta: # alpha-beta pruning
return v3
beta = min(beta, v3)
return v3
我看这两段代码似乎是等价的，不知道问题出在哪里
