Java如何使用递归实现树形结构的亲属关系查询并返回完整路径？

java如何用递归返回树结构的结果？

问题阐述：
需要实现一种算法，以树结构的形式返回给定名字的亲属关系链路。例如，以“秦朗”为搜索目标，结果应该返回“三国-曹操-秦朗”。

示例代码：

// 省略person类定义

public static void main(string[] args) {
    // 构建人物关系树
    person sunce = new
 person("孙策");
    person sunquan = new person("孙权");
    person sunjian = new person("孙坚");
    sunjian.setchildren(arrays.aslist(sunce, sunquan));

    person caopi = new person("曹丕");
    person caozhi = new person("曹植");
    person caozhang = new person("曹彰");
    person qinlang = new person("秦朗");

    person caocao = new person("曹操");
    caocao.setchildren(arrays.aslist(caopi, caozhi, caozhang, qinlang));


    person liufeng = new person("刘封");
    person liushan = new person("刘禅");

    person liubei = new person("刘备");
    liubei.setchildren(arrays.aslist(liufeng, liushan));

    person liuxun = new person("刘循");
    person liuzhang = new person("刘璋");
    liuzhang.setchildren(arrays.aslist(liuxun));
    person liuyan = new person("刘焉");
    liuyan.setchildren(arrays.aslist(liuzhang));

    person sanguo = new person("三国");
    sanguo.setchildren(arrays.aslist(sunjian, caocao, liubei, liuyan));

    // 使用递归算法查询并打印结果
    list p1 = query(sanguo, "刘");
    system.out.println(p1);
    list p2 = query(sanguo, "秦");
    system.out.println(p2);
    list p3 = query(sanguo, "孙策");
    system.out.println(p3);
}

// 递归查询返回亲属关系链路
public static list query(person person, string name) {
    list result = new arraylist<>();

    // 判空
    if(person.getname().contains(name)) {
        return arrays.aslist(person);
    } else {
        if(person.getchildren() != null) {
            for (person child : person.getchildren()) {
                result.addall(query(child, name));
            }
        }
    }

    return result;
}

改进要求：

用户提出希望返回的树结构中包含命中和未命中结果，且去掉未命中结果的子节点。

修改后代码：

// 省略person类定义

public static void main(string[] args) {
    // 构建人物关系树
    // ... 同上 ...

    // 使用递归算法生成树形结果并打印
    personvo sanguo = createtree(sanguo, -1);
    list resulttree = query(sanguo, "秦朗");
    system.out.println(json.tojsonstring(resulttree));
}

// 生成树形结构
private static personvo createtree(person person, int parentid) {
    personvo personvo = new personvo(person.getid(), parentid, person.getname());
    if (person.getchildren() != null) {
        for (person child : person.getchildren()) {
            personvo.getchildren().add(createtree(child, person.getid()));
        }
    }
    return personvo;
}

// 递归查询返回亲属关系链路
private static list query(personvo person, string name) {
    list result = new arraylist<>();
    if (person.getname().equals(name)) {
        result.add(person);
        return result;
    } else {
        for (personvo child : person.getchildren()) {
            result.addall(query(child, name));
        }
    }
    return result;
}

改进后效果：

qinlang 的搜索结果：

[{
    "id": 14
    "parentid": 4,
    "peoplename": "秦朗",
    "children": [
        {
            "id": 4,
            "parentid": 0,
            "peoplename": "曹操",
            "children": [
                {
                    "id": 0,
                    "parentid": -1,
                    "peoplename": "三国"
                }
            ]
        }
    ]
}]

sunjian 的搜索结果：

[{
    "id": 3,
    "parentId": 0,
    "peopleName": "孙坚",
    "children": [
        {
           "id": 0,
           "parentId": -1,
           "peopleName": "三国"
        }
    ]
}]

以上结果满足了用户提出的要求，返回的树形结构中包含所有命中和未命中的节点，且未命中的节点的子节点已被剔除。