func negamax(b game.Board, depth, alpha, beta int, color game.Color) (int, game.Move) {
if depth == 0 {
return scoreBoard(b, color), nullMove
}
moves := b.AvailableMoves(color)
if len(moves) == 0 {
return math.MinInt32 + 1, nullMove
}
var (
bestScore = math.MinInt32
bestMove game.Move
)
for _, i := range rand.Perm(len(moves)) {
val, _ := negamax(b.IfMove(moves[i]), depth-1, -beta, -alpha, color.Other())
val = -val
if val > bestScore {
bestScore = val
bestMove = moves[i]
}
if val > alpha {
alpha = val
}
if alpha >= beta {
break
}
}
return bestScore, bestMove
}
