递归 Java 数据结构 - 创建一个家族树的数组

Question

如何创建一个高效的递归函数 - 它将接受一个输入提要 - 可能有 1000 行长。成一个紧凑的数组。递归函数可能需要某种查找来确定当前员工 ID 之上是否有经理。

我正在尝试构建一个可能需要数组中的整个关系管理树的应用程序。

我需要想出一种方法来在输入数据馈送上创建递归函数，以将其映射到整理的输出数组。

//the input data may look something like this
[{
    "employeeId": "A1",
    "managerId": "B1",
    "employeeRole": "Sales0",
    "managerRole": "Sales1"
}, {
    "employeeId": "B1",
    "managerId": "C1",
    "employeeRole": "Sales1",
    "managerRole": "Sales2"
}, {
    "employeeId": "C1",
    "managerId": "D1",
    "employeeRole": "Sales2",
    "managerRole": "Sales3"
}, {
    "employeeId": "D1",
    "managerId": "",
    "employeeRole": "Sales3",
    "managerRole": "Sales4"
}]


//create a final output array like this
[
    "level1id": "A1",
    "level2id": "B1",
    "level3id": "C1",
    "level4id": "D1",
]

我现阶段的基本伪代码是这样的

void myMethod(String employeeId, String[] rawData, Map < String, String > dataMap) {

    //employeeId -- child id

    //rawData - from feed 

    //dataMap - the array being built to contain ALL relationships from grand child, parent, grandparent.



    getManager(employeeId, rawData) {

        //find the manager of the current employeeid

        //managerData[0] - manager id
        //managerData[1] - manager role

        return managerData;
    }


    managerData = getManager(employeeId, rawData);

    managerId = managerData[0];
    managerRole = managerData[1];

    dataMap.put(managerData[1], managerData[0]);
    // like [{"customerLevel1" : "SKDOL2"}]



    //if there is no manager id - the grandparent manager has been found
    if (managerId !== null)
        return;
    else {
        //this employeeid has a manager above them - loop through again until the grandparent is found (employee id with no manager) 
        myMethod(managerId, rawData, dataMap);
        return;
    }
}

Answer 1

您需要做一些工作来读取数据并对其进行解析并构建您的数据结构，但是对于类关系来说，这样的事情看起来很接近您应该需要的。

class Person {

    private final String id;

    public Person(String id) {
        this.id = id;
    }

    public String getId() {
        return id;
    }

}

class Employee extends Person {

    private final String managerId;

    public String getManagerId() {
        return managerId;
    }

    public Employee(String id, String managerId ) {
        super(id);
        this.managerId = managerId;
    }

}

class Manager extends Employee {

    private final String role;

    public String getRole() {
        return role;
    }

    public Manager(String id, String managerId, String role ) {
        super(id, managerId);
        this.role = role;
    }

}

/**
 * Use this to look up any person. 
 * 
 * Put ALL employees an managers in here as you read them.
 */
Map<String, Employee> personLookup = new HashMap<>();

Answer 2

我假设你的输入数据格式是 json，所以你需要json.jar。

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

import org.json.JSONArray;
import org.json.JSONObject;

public class OrgnizationTree {

    HashMap<String, ArrayList<Employee>> jsonDataMap = new HashMap<String, ArrayList<Employee>>();
    HashMap<String, Employee> employeeMap = new HashMap<String, Employee>();
    Employee root;

    public void buildTree(String jsonData) throws Exception {
        JSONArray array = new JSONArray(jsonData);
        for (int i = 0; i < array.length(); i++) {
            JSONObject object = (JSONObject) array.get(i);
            String employeeId = object.get("employeeId").toString();
            String managerId = object.get("managerId").toString();
            if (managerId == null || managerId.isEmpty()) {
                root = new Employee(employeeId, null);
            } else {
                Employee subordinate = new Employee(employeeId);
                if (jsonDataMap.containsKey(managerId)) {
                    jsonDataMap.get(managerId).add(subordinate);
                } else {
                    ArrayList<Employee> subordinates = new ArrayList<Employee>();
                    subordinates.add(subordinate);
                    jsonDataMap.put(managerId, subordinates);
                }
            }
        }
        for (Employee subordinate : jsonDataMap.get(root.getId())) {
            root.addSubordinate(subordinate);
            subordinate.setManager(root);
            employeeMap.put(root.getId(), root);
            buildSubTree(subordinate);
        }
    }

    public void buildSubTree(Employee manager) {
        List<Employee> subordinates = jsonDataMap.get(manager.getId());
        if (subordinates != null) {
            for (Employee subordinate : subordinates) {
                subordinate.setManager(manager);
                manager.addSubordinate(subordinate);
                buildSubTree(subordinate);
            }
        }
        employeeMap.put(manager.getId(), manager);
    }

    public Employee getManager(String employeeId) {
        Employee employee = employeeMap.get(employeeId);
        Employee manager = employee.getManager();
        return manager;
    }

    public Employee getEmployee(String employeeId) {
        return employeeMap.get(employeeId);
    }

    public Employee getRoot() {
        return root;
    }

    public class Employee {
        String id;
        Employee manager;
        List<Employee> subordinates;
        Integer level;

        Employee(String id, Employee manager) {
            this.id = id;
            this.manager = manager;
            if (manager == null) {
                level = 0;
            } else {
                level = manager.level + 1;
            }
        }

        Employee(String id) {
            this.id = id;
        }

        public void addSubordinate(Employee subordinate) {
            if (subordinates == null) {
                subordinates = new ArrayList<Employee>();
            }
            subordinates.add(subordinate);
        }

        public String getId() {
            return this.id;
        }

        public Employee getManager() {
            return manager;
        }

        public void setManager(Employee manager) {
            this.manager = manager;
            this.level = manager.level + 1;
        }

    }

    public static void main(String[] args) throws Exception {
        String jsonData = "[{'employeeId': 'A1', 'managerId': 'B1'}, {'employeeId': 'B1', 'managerId': 'C1'}, "
                + "{'employeeId': 'C1', 'managerId': 'D1'}, {'employeeId': 'D1', 'managerId': ''}]";
        OrgnizationTree t = new OrgnizationTree();
        t.buildTree(jsonData);
        System.out.println(t.getManager("A1").getId());
        System.out.println(t.getEmployee("A1").getManager().getId());
        System.out.println(t.getRoot().getId());
    }

}