CareerCup

public class Employee {
private int ID;
private String firstName;
private String lastName;
private Employee manager;
private List<Employee> subordinates;

public Employee(int id, String firstName, String lastName, Employee manager)
{
    this.ID = id;
    this.firstName = firstName;
    this.lastName = lastName;
    this.manager = manager;
    this.subordinates = new ArrayList<Employee>();
}
/***
gettter and setter methods are ommitted 
***/

public void addSubordinate(Employee emp){
  if(emp != null){
     this.subordinates.add(emp);
}
}

public void printSubordinate(){

if(subordinates == null || subordinates.isEmpty()){
System.out.println("There are no subordinates");
}else{
  
 for(Employee e : subordinates){
            System.out.println(e.getFirstName + " " + e.getLastName());     
}
}
}
}

This is more of a database schema question, wherein subordinates of a employee is represented as foreign key in the employee table.

Representing in OOP model,
Every employee can have a vector to store references of his subordinates, the only issue with this, to store references of all the subordinates in a vector of employee class it needs all subordinate objects must have been instantiated.

Program should be written in Java/C++ using classes and objects

it is not good,it is a tree traverse problem.

it is not good,it is a tree traverse problem.

package emp;

import java.util.HashSet;
import java.util.Set;

public class Employee {

    int id;
    String firstName;
    String lastName;
    Employee manager;
    Set subordinates = new HashSet<Employee>();

    Employee(int id, String firstName, String lastName) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    void addManager(Employee manager) {
        this.manager = manager;
        manager.subordinates.add(this);
    }

    void addSubordinate(Employee subordinate) {
        this.subordinates.add(subordinate);
        subordinate.manager = this;
    }

    void findDetails() {
        if (this.manager != null) {
            System.out.println("Manager is : " + this.manager);
        } else {
            System.out.println("NO manager for " + this);
        }
        if (this.subordinates.size() > 0) {
            System.out.println("***SUB ORDINATES***");
            for (Object subordinate : this.subordinates) {
                Employee emp = (Employee) subordinate;
                System.out.println(emp);
            }
        } else {
            System.out.println("No subordinates for : " + this);
        }
    }

    @Override
    public String toString() {
        return this.id + " : " + this.firstName + "." + this.lastName;
    }

    public static void main(String argc[]) {
        Employee a = new Employee(1, "a", "aa");
        Employee b = new Employee(2, "b", "bb");
        Employee c = new Employee(3, "c", "cc");
        Employee d = new Employee(4, "d", "dd");
        Employee e = new Employee(5, "e", "ee");
        Employee f = new Employee(6, "f", "ff");
        Employee g = new Employee(7, "g", "gg");

        a.addSubordinate(b);
        a.addSubordinate(c);
        b.addSubordinate(e);
        b.addSubordinate(f);
        c.addSubordinate(g);

        a.findDetails();

    }
}

import java.util.HashSet;
import java.util.Set;

public class Employee {

    int id;
    String firstName;
    String lastName;
    Employee manager;
    Set subordinates = new HashSet<Employee>();

    Employee(int id, String firstName, String lastName) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    void addManager(Employee manager) {
        this.manager = manager;
        manager.subordinates.add(this);
    }

    void addSubordinate(Employee subordinate) {
        this.subordinates.add(subordinate);
        subordinate.manager = this;
    }

    void findDetails() {
        if (this.manager != null) {
            System.out.println("Manager is : " + this.manager);
        } else {
            System.out.println("NO manager for " + this);
        }
        if (this.subordinates.size() > 0) {
            System.out.println("***SUB ORDINATES***");
            for (Object subordinate : this.subordinates) {
                Employee emp = (Employee) subordinate;
                System.out.println(emp);
            }
        } else {
            System.out.println("No subordinates for : " + this);
        }
    }

    @Override
    public String toString() {
        return this.id + " : " + this.firstName + "." + this.lastName;
    }

    public static void main(String argc[]) {
        Employee a = new Employee(1, "a", "aa");
        Employee b = new Employee(2, "b", "bb");
        Employee c = new Employee(3, "c", "cc");
        Employee d = new Employee(4, "d", "dd");
        Employee e = new Employee(5, "e", "ee");
        Employee f = new Employee(6, "f", "ff");
        Employee g = new Employee(7, "g", "gg");

        a.addSubordinate(b);
        a.addSubordinate(c);
        b.addSubordinate(e);
        b.addSubordinate(f);
        c.addSubordinate(g);

        a.findDetails();

    }
}

its a composite design pattern question - head first java

How about this.. any thoughts??????


import java.util.ArrayList;

public class Employee {
static ArrayList<Employee> al = new ArrayList();
private String id, fname, lname, mgrid;

public String getId() {
return id;
}

public void setId(String id) {
this.id = id;
}

public String getFname() {
return fname;
}

public void setFname(String fname) {
this.fname = fname;
}

public String getLname() {
return lname;
}

public void setLname(String lname) {
this.lname = lname;
}

public String getMgrid() {
return mgrid;
}

public void setMgrid(String mgrid) {
this.mgrid = mgrid;
}

public static void main(String[] args) {
// Loading the employees
Employee vo = new Employee();
vo.setFname("EmpFname");
vo.setLname("EmpLname");
vo.setId("1");
vo.setMgrid("100");
al.add(vo);
Employee vo1 = new Employee();
vo1.setFname("EmpFname2");
vo1.setLname("EmpLname2");
vo1.setId("3");
vo1.setMgrid("100");
al.add(vo1);
Employee vo2 = new Employee();
vo2.setFname("EmpLname3");
vo2.setLname("EmpLname3");
vo2.setId("4");
vo2.setMgrid("101");
al.add(vo2);
Employee vo3 = new Employee();
vo3.setFname("EmpLname4");
vo3.setLname("EmpLname4");
vo3.setId("6");
vo3.setMgrid("101");
al.add(vo3);
Employee vo4 = new Employee();
vo4.setFname("EmpLnameMgr");
vo4.setLname("EmpLnameMgr");
vo4.setId("100");
vo4.setMgrid("1000");
al.add(vo4);

showSubordinates("100");// this method shows the subordinates for Mgr ID
// which is passed.

}

public static void showSubordinates(String EmpID) {
boolean flg = false;
for (int i = 0; i < al.size(); i++) {
Employee vo = al.get(i);
if (vo.getMgrid().equals(EmpID)) {
flg = true;
System.out.println("Subordinate for Mgr " + EmpID + " is: "
+ vo.getFname() + ", " + vo.getLname() + ", EmpID: "
+ vo.getId());
}
}
if (!flg) {
System.out.println("No Subordinates found");
}

}

}