阳江网上房地产官网_长沙专业做网络的公司_指数分布的期望和方差_最新的即时比分

import java.util.*;

// 定义树节点类
class TreeNode {
int id;
int pid;
String name;
List children;

public TreeNode(int id, int pid, String name) {this.id = id;this.pid = pid;this.name = name;this.children = new ArrayList<>();
}

}

public class TreeNodeConverter {
public static List convertToTree(List nodes) {
// 存储节点映射
Map<Integer, TreeNode> nodeMap = new HashMap<>();
// 存储根节点
List rootNodes = new ArrayList<>();

    // 首先将所有节点放入映射中for (TreeNode node : nodes) {nodeMap.put(node.id, node);}// 构建树结构for (TreeNode node : nodes) {int pid = node.pid;if (pid == 0) {// 如果父节点 ID 为 0，说明是根节点rootNodes.add(node);} else {// 找到父节点TreeNode parent = nodeMap.get(pid);if (parent != null) {parent.children.add(node);}}}return rootNodes;
}public static void main(String[] args) {List<TreeNode> nodes = new ArrayList<>();nodes.add(new TreeNode(1, 0, "根节点"));nodes.add(new TreeNode(2, 1, "子节点1"));nodes.add(new TreeNode(3, 1, "子节点2"));nodes.add(new TreeNode(4, 2, "孙节点1"));nodes.add(new TreeNode(5, 2, "孙节点2"));nodes.add(new TreeNode(6, 3, "孙节点3"));nodes.add(new TreeNode(7, 3, "孙节点4"));nodes.add(new TreeNode(8, 4, "曾孙节点1"));nodes.add(new TreeNode(9, 4, "曾孙节点2"));nodes.add(new TreeNode(10, 5, "曾孙节点3"));List<TreeNode> tree = convertToTree(nodes);// 打印树结构printTree(tree, 0);
}private static void printTree(List<TreeNode> nodes, int level) {for (TreeNode node : nodes) {StringBuilder indent = new StringBuilder();for (int i = 0; i < level; i++) {indent.append("  ");}System.out.println(indent + node.name);printTree(node.children, level + 1);}
}

}