如何用Java编写惰性删除二叉树的findMinimum

class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;
    boolean deleted;

    public TreeNode(int val) {
        this.val = val;
        this.left = null;
        this.right = null;
        this.deleted = false;
    }
}

public TreeNode findMinimum(TreeNode root) {
    if (root == null) {
        return null;
    }

    TreeNode current = root;
    while (current.left != null) {
        current = current.left;
        if (!current.deleted) {
            return current;
        }
    }

    return null;
}

public static void main(String[] args) {
    TreeNode root = new TreeNode(5);
    root.left = new TreeNode(3);
    root.right = new TreeNode(7);
    root.left.left = new TreeNode(2);
    root.left.right = new TreeNode(4);
    root.right.left = new TreeNode(6);
    root.right.right = new TreeNode(8);

    root.left.deleted = true; // 标记节点3为删除状态

    Solution solution = new Solution();
    TreeNode minimum = solution.findMinimum(root);
    if (minimum != null) {
        System.out.println("Minimum value: " + minimum.val);
    } else {
        System.out.println("No minimum value found.");
    }
}