解决方案
算法思路
为了判断树状结构中的列表是第几级，我们可以采用递归的方式遍历每个节点，计算其深度。具体来说，对于每个节点，我们可以向上遍历其父节点，直到根节点，同时累计深度值。最终得到的深度值就是该节点所处的级别。

代码示例
下面是一个简单的Java代码示例，用于判断树状结构中的节点是第几级：

public class TreeNode {private int id;private int parentId;public TreeNode(int id, int parentId) {this.id = id;this.parentId = parentId;}public int getId() {return id;}public int getParentId() {return parentId;}
}public class TreeUtils {public static int getLevel(TreeNode node, List<TreeNode> nodeList) {int level = 1;int parentId = node.getParentId();while (parentId != 0) {for (TreeNode n : nodeList) {if (n.getId() == parentId) {parentId = n.getParentId();level++;break;}}}return level;}
}public class Main {public static void main(String[] args) {List<TreeNode> nodeList = new ArrayList<>();nodeList.add(new TreeNode(1, 0));nodeList.add(new TreeNode(2, 1));nodeList.add(new TreeNode(3, 1));nodeList.add(new TreeNode(4, 2));TreeNode node = nodeList.get(3);int level = TreeUtils.getLevel(node, nodeList);System.out.println("Node " + node.getId() + " is at level " + level);}
}