java多线程计算汉诺塔

下面是一个使用 Java 多线程计算汉诺塔的示例代码：

public class HanoiTower {

    private static final int NUM_DISKS = 3;
    private static final int NUM_PEGS = 3;

    public static void main(String[] args) {
        HanoiSolver solver = new HanoiSolver(NUM_DISKS, NUM_PEGS);
        solver.solve();
    }

    private static class HanoiSolver {

        private final int numDisks;
        private final int numPegs;
        private final List<Stack<Integer>> pegs;
        private final AtomicInteger numMoves;

        public HanoiSolver(int numDisks, int numPegs) {
            this.numDisks = numDisks;
            this.numPegs = numPegs;
            this.pegs = new ArrayList<>();
            for (int i = 0; i < numPegs; i++) {
                pegs.add(new Stack<>());
            }
            for (int i = numDisks; i >= 1; i--) {
                pegs.get(0).push(i);
            }
            this.numMoves = new AtomicInteger(0);
        }

        public void solve() {
            executeTask(new HanoiTask(numDisks, 0, 1, 2));
        }

        private void executeTask(HanoiTask task) {
            if (task.numDisks == 1) {
                moveSingleDisk(task.fromPeg, task.toPeg);
            } else {
                int newPeg = getNewPeg(task.fromPeg, task.toPeg);
                executeTask(new HanoiTask(task.numDisks - 1, task.fromPeg, newPeg, task.toPeg));
                moveSingleDisk(task.fromPeg, task.toPeg);
                executeTask(new HanoiTask(task.numDisks - 1, newPeg, task.toPeg, task.fromPeg));
            }
        }

        private void moveSingleDisk(int fromPeg, int toPeg) {
            int disk = pegs.get(fromPeg).pop();
            pegs.get(toPeg).push(disk);
            System.out.println("Move disk " + disk + " from peg " + fromPeg + " to peg " + toPeg);
            numMoves.incrementAndGet();
        }

        private int getNewPeg(int fromPeg, int toPeg) {
            for (int i = 0; i < numPegs; i++) {
                if (i != fromPeg && i != toPeg) {
                    return i;
                }
            }
            throw new IllegalStateException("No available peg");
        }

        private class HanoiTask {
            private final int numDisks;
            private final int fromPeg;
            private final int toPeg;
            private final int viaPeg;

            public HanoiTask(int numDisks, int fromPeg, int toPeg, int viaPeg) {
                this.numDisks = numDisks;
                this.fromPeg = fromPeg;
                this.toPeg = toPeg;
                this.viaPeg = viaPeg;
            }
        }

    }

}

这里的 `HanoiSolver` 类使用一个 `Stack` 对象来表示每个针上的盘子，并使用 `AtomicInteger` 对象来记录移动次数。`HanoiTask` 类表示需要移动的盘子数量以及移动的起始针、目标针和中间针。在 `executeTask()` 方法中，如果任务中只有一个盘子，就直接将盘子从起始针移动到目标针；否则，先将任务拆分成三个子任务，分别将 `numDisks - 1` 个盘子从起始针移动到中间针，将一个盘子从起始针移动到目标针，最后再将 `numDisks - 1` 个盘子从中间针移动到目标针。