关于#java#的问题，如何解决？

Question

各位，求一个java算法，根据json数据，返回树的所有路径
如下json返回 A-B-C-D和A-E
json如下：
{
"result":{

    "relations":[
        
        {
            "source":"A",
            "target":"B"
        },
        {
            "source":"B",
            "target":"C"
        },
        {
            "source":"C",
            "target":"D"
        },
        {
            "source":"A",
            "target":"E"
        }
    ]
},
"status":{
    "code":0,
    "desc":"success"
}

}

Answer 1

仅供参考，望采纳：

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

class Main {
  static class Node {
    String name;
    List<Node> children = new ArrayList<>();
  }

  static Map<String, Node> nodes = new HashMap<>();

  static void buildTree(String source, String target) {
    Node sourceNode = nodes.get(source);
    if (sourceNode == null) {
      sourceNode = new Node();
      sourceNode.name = source;
      nodes.put(source, sourceNode);
    }

    Node targetNode = nodes.get(target);
    if (targetNode == null) {
      targetNode = new Node();
      targetNode.name = target;
      nodes.put(target, targetNode);
    }

    sourceNode.children.add(targetNode);
  }

  static void getPaths(Node root, String path, List<String> paths) {
    path += root.name + "-";
    if (root.children.isEmpty()) {
      paths.add(path.substring(0, path.length() - 1));
      return;
    }

    for (Node child : root.children) {
      getPaths(child, path, paths);
    }
  }

  public static void main(String[] args) {
    // 根据JSON数据中的关系构建树
    List<Map<String, String>> relations = getRelationsFromJson();
    for (Map<String, String> relation : relations) {
      buildTree(relation.get("source"), relation.get("target"));
    }

    // 获取根节点（A）
    Node root = nodes.get("A");

    // 获取从根开始的所有路径
    List<String> paths = new ArrayList<>();
    getPaths(root, "", paths);
    System.out.println(paths);
  }
}