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intermmediate

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This commit is contained in:
Michael Peters 2022-11-26 05:33:39 -08:00
parent 022cb43c92
commit 720bb5b566
1 changed files with 49 additions and 26 deletions
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chess.py
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@ -11,6 +11,9 @@ ranks = 'RNBQKBNR'
def next_turn(turn): def next_turn(turn):
return 'B' if turn == 'W' else 'W' return 'B' if turn == 'W' else 'W'
def get_turn_pieces(turn, whites, blacks):
return (whites, blacks) if turn == 'W' else (blacks, whites)
def create_board(): def create_board():
whites = {} whites = {}
whites.update({vec2(c, 0): rank for (c, rank) in zip(range(8), ranks)}) whites.update({vec2(c, 0): rank for (c, rank) in zip(range(8), ranks)})
@ -40,14 +43,19 @@ def get_human_move(turn):
s = input(turn + ' to move: ') s = input(turn + ' to move: ')
return tuple(map(vec2_from_text, s.split())) return tuple(map(vec2_from_text, s.split()))
def get_start_move(start_move):
print(start_move)
return tuple(map(vec2_from_text, start_move.split()))
def get_computer_move(turn, whites, blacks): def get_computer_move(turn, whites, blacks):
return random.choice(get_valid_moves(turn, whites, blacks)) return random.choice(get_valid_moves(turn, whites, blacks))
def get_valid_dsts(src, whites, blacks): def get_valid_dsts(src, turn, whites, blacks):
# todo: castling # todo: castling
# todo: en passant # todo: en passant
is_white_turn = src in whites # todo: promotion
self_pieces, oppo_pieces = (whites, blacks) if is_white_turn else (blacks, whites) self_pieces, oppo_pieces = get_turn_pieces(turn, whites, blacks)
piece = self_pieces[src] piece = self_pieces[src]
valid_dsts = set() valid_dsts = set()
@ -69,8 +77,8 @@ def get_valid_dsts(src, whites, blacks):
delta += dir delta += dir
if piece == 'P': # Pawn if piece == 'P': # Pawn
dy = 1 if is_white_turn else -1 dy = 1 if turn == 'W' else -1
sy = 1 if is_white_turn else 6 sy = 1 if turn == 'W' else 6
dst_fw1 = src + vec2(0, dy) dst_fw1 = src + vec2(0, dy)
dst_fw2 = src + vec2(0, dy * 2) dst_fw2 = src + vec2(0, dy * 2)
dst_tkl = src + vec2(-1, dy) dst_tkl = src + vec2(-1, dy)
@ -99,10 +107,10 @@ def get_valid_dsts(src, whites, blacks):
def get_valid_moves(turn, whites, blacks): def get_valid_moves(turn, whites, blacks):
self_pieces = whites if turn == 'W' else blacks self_pieces = whites if turn == 'W' else blacks
return [(src, dst) for src in self_pieces for dst in get_valid_dsts(src, whites, blacks)] return [(src, dst) for src in self_pieces for dst in get_valid_dsts(src, turn, whites, blacks)]
def next_board(src, dst, whites, blacks): def next_board(src, dst, turn, whites, blacks):
self_pieces, oppo_pieces = (whites, blacks) if src in whites else (blacks, whites) self_pieces, oppo_pieces = get_turn_pieces(turn, whites, blacks)
self_pieces[dst] = self_pieces[src] # Move src -> dst self_pieces[dst] = self_pieces[src] # Move src -> dst
del self_pieces[src] # Remove src del self_pieces[src] # Remove src
if dst in oppo_pieces: # Remove dst if it was an opponent if dst in oppo_pieces: # Remove dst if it was an opponent
@ -111,14 +119,14 @@ def next_board(src, dst, whites, blacks):
# Valid moves filtered such that the opponent cannot take the current player's king # Valid moves filtered such that the opponent cannot take the current player's king
def get_legal_moves(turn, whites, blacks): def get_legal_moves(turn, whites, blacks):
self_pieces, oppo_pieces = (whites, blacks) if turn == 'W' else (blacks, whites) self_pieces, oppo_pieces = get_turn_pieces(turn, whites, blacks)
valid_moves = get_valid_moves(turn, whites, blacks) valid_moves = get_valid_moves(turn, whites, blacks)
legal_moves = [] legal_moves = []
for src, dst in valid_moves: for src, dst in valid_moves:
n_whites, n_blacks = next_board(src, dst, whites.copy(), blacks.copy()) n_whites, n_blacks = next_board(src, dst, turn, whites.copy(), blacks.copy())
n_turn = next_turn(turn) n_turn = next_turn(turn)
n_self_pieces, n_oppo_pieces = (n_whites, n_blacks) if n_turn == 'W' else (n_blacks, n_whites) n_self_pieces, n_oppo_pieces = get_turn_pieces(n_turn, n_whites, n_blacks)
n_valid_moves = get_valid_moves(n_turn, whites, blacks) n_valid_moves = get_valid_moves(n_turn, n_whites, n_blacks)
legal = True legal = True
for n_src, n_dst in n_valid_moves: for n_src, n_dst in n_valid_moves:
if n_dst in n_oppo_pieces and n_oppo_pieces[n_dst] == 'K': if n_dst in n_oppo_pieces and n_oppo_pieces[n_dst] == 'K':
@ -129,7 +137,7 @@ def get_legal_moves(turn, whites, blacks):
return legal_moves return legal_moves
def is_in_check(turn, whites, blacks): def is_in_check(turn, whites, blacks):
self_pieces, oppo_pieces = (whites, blacks) if turn == 'W' else (blacks, whites) self_pieces, oppo_pieces = get_turn_pieces(turn, whites, blacks)
n_turn = next_turn(turn) n_turn = next_turn(turn)
threat_moves = get_valid_moves(n_turn, whites, blacks) threat_moves = get_valid_moves(n_turn, whites, blacks)
for src, dst in threat_moves: for src, dst in threat_moves:
@ -139,28 +147,43 @@ def is_in_check(turn, whites, blacks):
turn = 'W' turn = 'W'
whites, blacks = create_board() whites, blacks = create_board()
start_moves = [
'D2 D4',
'E7 E5',
'D4 E5',
'D8 E7',
'E5 E6',
'E7 E6',
'E2 E4',
'F7 F5',
#'E4 F5' # Should not be legal
]
while True: while True:
print(turn, 'to move') print(turn, 'to move')
print_board(whites, blacks) print_board(whites, blacks)
legal_moves = get_legal_moves(turn, whites, blacks) legal_moves = get_legal_moves(turn, whites, blacks)
print(len(legal_moves), 'valid moves') print(len(legal_moves), 'legal moves')
for src, dst in legal_moves: self_pieces, oppo_pieces = get_turn_pieces(turn, whites, blacks)
print(src, '->', dst)
if len(legal_moves) == 0: if len(legal_moves) == 0:
print('game is over') print('game is over')
break break
# if turn == 'W': # if turn == 'W':
while True: if len(start_moves):
try: src, dst = get_start_move(start_moves.pop(0))
src, dst = get_human_move(turn) else:
if not (src, dst) in legal_moves: for src, dst in legal_moves:
print('invalid move') print(f"{self_pieces[src]} {src}{'x' if dst in oppo_pieces else ' '}{dst}")
else: while True:
break try:
except ValueError: src, dst = get_human_move(turn)
print('invalid input') if not (src, dst) in legal_moves:
print('not a legal move')
else:
break
except ValueError:
print('invalid input')
# else: # else:
# src, dst = get_computer_move(turn, whites, blacks) # src, dst = get_computer_move(turn, whites, blacks)
whites, blacks = next_board(src, dst, whites, blacks) whites, blacks = next_board(src, dst, turn, whites, blacks)
turn = next_turn(turn) turn = next_turn(turn)