chess-alpha-beta
Chess solver based on minimax algorithm with alpha-beta pruning optimization. For the minimax details refer to here.
White player is maximizer. Black is minimizer. Total score evaluated in here.
One can control computer's intelligence by increasing or decreasing DEPTH variable. Be aware: the algorithm working time depends on DEPTH exponentially.
Build
& cargo run --release -- --depth 6 --mode wubc
===== 0-th move:
8| r n b q k b n r
7| p p p p p p p p
6| . . . . . . . .
5| . . . . . . . .
4| . . . . . . . .
3| . . . . . . . .
2| P P P P P P P P
1| R N B Q K B N R
------------------
| a b c d e f g h
legal_moves = ["a2a3", "a2a4", "b1a3", "b1c3", "b2b3", "b2b4",
"c2c3", "c2c4", "d2d3", "d2d4", "e2e3", "e2e4", "f2f3", "f2f4",
"g1f3", "g1h3", "g2g3", "g2g4", "h2h3", "h2h4"], len = 20
Type white move: g1f3
Black value = 199
black move = g8f6
===== 2-th move:
8| r n b q k b . r
7| p p p p p p p p
6| . . . . . n . .
5| . . . . . . . .
4| . . . . . . . .
3| . . . . . N . .
2| P P P P P P P P
1| R N B Q K B . R
------------------
| a b c d e f g h
legal_moves = ["a2a3", "a2a4", "b1a3", "b1c3", "b2b3", "b2b4",
"c2c3", "c2c4", "d2d3", "d2d4", "e2e3", "e2e4", "f3d4", "f3e5",
"f3g1", "f3g5", "f3h4", "g2g3", "g2g4", "h1g1", "h2h3", "h2h4"
], len = 22
Type white move: c2c4
Black value = 167
black move = d7d5
...
(two hours later)
...
==== 52-th move:
8| . . . r k b . r
7| p p . . p . p p
6| . . p . n . . R
5| . . . . . . . .
4| . P n . . . . .
3| P . . . . . . .
2| . . p . . P . .
1| R . . . K . q .
------------------
| a b c d e f g h
legal_moves = ["e1e2"], len = 1
Type white move: e1e2
Black value = -1006731
black move = g1d1
===== 54-th move:
8| . . . r k b . r
7| p p . . p . p p
6| . . p . n . . R
5| . . . . . . . .
4| . P n . . . . .
3| P . . . . . . .
2| . . p . K P . .
1| R . . q . . . .
------------------
| a b c d e f g h
legal_moves = ["a1d1"], len = 1
Type white move: a1d1
Black value = -1006731
black move = c2d1q
Chechmate! Black won!