Question

Your assignment is to write a C++ program to read a text file containing the information of the employees of a company, load them into memory and perform some basic human resources operations. This assignment will help you practice: multiple file programming, classes, public and private methods, dynamic memory allocation, constructors and destructors, singly linked list and files.

Implementation

This lab assignment gives you the opportunity to practice creating classes and using dynamic memory in one of the required classes. There are two classes to implement Employee and Company. #the Company will hold a linked list of Employees. This list of employees is modeled using linked nodes of Employee* (pointers to Employees). These employees are created dynamically when they are added to the list.

You will create the following files:

• menu.cpp: contains your main function
• employee.h: contains the Employee class declaration
• employee.cpp: contains the Employee class method definitions
• company.h: contains the Company class declaration
• company.cpp: contains the Company class method definitions

Class Descriptions

Employee

Notice there are no changes from previous Employee implementation

Access	Member	Description
Private	_id: unsigned int	ID
Private	_name: string	Name
Private	_salary: double	Salary
Private	_managerId: unsigned int	Manager ID
Public	Employee(unsigned int, const string&, double, unsigned int=0	Creates an employee using the values given by the parameters. The last parameter represents the manager ID. If the name parameter is an empty string, the constructor should initialize the name to “***”
Public	Employee(const Employee&)	Copy constructor for Employee
Public	GetID(): unsigned int	Accessor for ID
Public	GetName(): string	Accessor for name
Public	GetSalary():double	Accessor for salary
Public	GetManagerId(): unsigned int	Accessor for Manager ID
Public	ToString():string	Returns a string representation of the Employee. (see after the table for the details on this method)
Public	Raise(double):void	Gives a raise to the employee, adding the specified amount to his or her current salary.
Public	Equals(const Employee&)	Returns true if the employee specified by the parameter has same ID as current object.
Public	Read(istream&):bool	Reads an employee from the istream returning true/false depending on whether read was successful.
Public	Write(ostream&):void	Writes the information about an employee, separated by spaces, to the ostream.
Public	~Employee()	Destructor, empty

Company

Access	Member	Description
Private	struct Node{Employee* data; Node* next; }	Represents the node type that will become each of the links of the linked list.
Private	_head: Node*	Head of the list, is the pointer to the first element of the list.
Private	_size: unsigned int	The number of actual employees in the list. In the beginning, there are no employees.
Private	Company(const Company&)	Copy constructor private to prevent copies from 'outside' the class.
Public	Company()	Constructor for Company. Sets the _size to zero, initializes _head to nullptr.
Public	AddEmployee(unsigned int, const string&, double, unsigned int=0): bool	Adds an employee to the list (to the correct position, the list must always be sorted). The parameters specify the information about the employee. Returns true if it was able to add it, false otherwise.
Public	AddEmployee(const Employee&): bool	Adds the specified employee to the list(to the correct position, the list must always be sorted). Returns true if it was able to add it, false otherwise.
Public	FindById(unsigned int): int	Uses binary search to find an employee using the ID given in the parameter. Returns -1 if the employee is not found. If it is found returns the position of that employee.
Public	FindByName(const string&, unsigned int=0)	Uses linear search starting from the position specified by the second parameter to find the first occurrence of the given name in the Array. Returns -1 if the employee is not found. If it is found returns the position of that employee.
Public	Read(istream&):int	Reads an istream and extracts all the employees’ data from there, and adds the employees to existing list of employees. Returns the number of employees read.
Public	Write(ostream&):int	Writes all the available employees to the ostream. Returns the number of employees written.
Public	IsFull():bool	Always returns false.
Public	Get(unsigned int): Employee*	Returns a pointer to the Employee at the position specified by the parameter. If the position is invalid, it returns nullptr. The referenced object belongs to the object and should not be “deleted” by the client.
Public	GetEmployeeCount():unsigned int	Returns the number of employees in the Company (_size)
Public	~Company()	Frees the memory by releasing all the dynamically created employees in the array.

Employee::ToString(), returns a formatted string following the following format:

ID: 1 Name: Peter Salary: 250 Manager ID: 0

Widths:

• ID: 4
• Name: 10
• Salary: 10
• Manager ID: 4

Program Menu

Your program should output the following menu:

1. Load from File
2. Save to File
3. List all Employees
4. Search by Name
5. Search by ID
6. Find Employee Boss Information
7. Add new Employee
8. Check if Database is Full
9. Exit

Menu Option	Description
Load a Company File	Asks the user for the file name containing the employee’s information. TXT files containing sample company information are included with this Lab document.
Save Company Data to File	Saves the current information in memory to a file. The program asks the user for the file name where the user wants to save this.
List all Employees	Lists all the employees stored in memory. Uses company ToString method to display them.
Search by Name	The user inputs a name, then, using the method FindFirstByName the program displays all employees with that name using ToString method.
Search by ID	The user inputs an ID, then, using the method FindById the program displays the employee with that ID using ToString method or that it did not find that ID.
Find Employee Boss Information	The user inputs an ID, then, using the method FindById the program displays the employee ID using GetID method or that it did not find that ID. Once the employee is found, gets the manager’s ID, and with it searches that ID and gets the manager’s rest of the information. Displays the manager information using ToString method.
Add New Employee	Requests the user to enter the following information about the employee: ID, name, salary and manager ID. Manager ID is zero for employees without boss. Only adds employees if it fits in the array! Only adds employees with ID that is not already in the list
Check if Database is Full	Displays a message indicating if the database is full, or not full.
Exit	Exits the program

Answer 1

Employee class Read and Write is not implemented as Company class is implementing same functions. Both will be same. As requested, I created a new function FindByIdBinarySearch(), you can use either Find functions, or you can replace existing FindById with that of FindByIdBinarySearch.

Employee.cpp #include "Employee.h" #include <sstream> #include <iomanip> using namespace std; Employee::Employee(const Employee &emp) {    this->_id = emp._id;    this->_name = emp._name;    this->_salary = emp._salary;    this->_managerId = emp._managerId; } uint Employee::getId() const {    return _id; } uint Employee::getManagerId() const {    return _managerId; } const string& Employee::getName() const {    return _name; } Employee::Employee(uint id, const string &name, double salary, uint managerId) {    this->_id = id;    this->_name = name;    this->_salary = salary;    this->_managerId = managerId; } double Employee::getSalary() const {    return _salary; } Employee::~Employee() { } string Employee::ToString() {    stringstream ss;    ss <<fixed<< "ID: "<<setw(4)<<setfill(' ')<<this->_id<<" Name: "<<            setw(10)<<this->_name+" Salary: "<<            setw(10)<<setprecision(2)<<this->_salary<<" Manager ID: "<<            setw(4)<<this->_managerId ;    return ss.str(); } void Employee::Raise(double raise) {    this->_salary += raise; } bool Employee::Equals(const Employee &anotherEmp) {    return (this->_id==anotherEmp._id); } bool Employee::Read(istream &in) {    return false; } void Employee::Write(ostream &out) { }

Employee.h #ifndef EMPLOYEE_H_ #define EMPLOYEE_H_ #include <string> typedef unsigned int uint; using namespace std; class Employee { private:    uint _id;    string _name;    double _salary;    uint _managerId; public:    Employee(uint, const string&, double, uint=0);    Employee(const Employee &other);    virtual ~Employee();    uint getId() const;    uint getManagerId() const;    const string& getName() const;    double getSalary() const;    string ToString();    void Raise(double);    bool Equals(const Employee&);    bool Read(istream &);    void Write(ostream &); }; #endif /* EMPLOYEE_H_ */

Company.cpp #include "Company.h" #include <sstream> #include <iostream> #include <iomanip> using namespace std; Company::Company() {    this->_head = NULL;    this->_size = 0; } Company::~Company() { } Company::Company(const Company &company) {    this->_head = company._head;    this->_size = company._size; } bool Company::AddEmployee(const Employee &emp) {    Node * empNode = new Node, * currNode, *prevNode = NULL;    // set employee data    empNode->data = new Employee(emp);    // set next node as null    empNode->next = NULL;    // set head node, if list is empty    if(_head == NULL)    {        _head = empNode;        _size = 1;    }    // else add to the end of list    else    {        // start from head node        currNode = _head;        // when node in the list is not null        while(currNode != NULL)        {            // No two IDs should be same            // Insert at position where new empId is less than the next in list            if(emp.getId() < currNode->data->getId())            {                // insert as head                if(prevNode == NULL)                {                    // head as second in the list                    empNode->next = _head;                    // set new node as head node                    _head = empNode;                }                else                {                    // set new node as next to previous                    prevNode->next = empNode;                    // set current node as next to new                    empNode->next = currNode;                }                // increment employee count                _size++;                // return true                return true;            }            // point current node to previous            prevNode = currNode;            // point next node in the list to current            currNode = currNode->next;        }        // set empNode as last in list        prevNode->next = empNode;        // increment employee count        _size++;        // return true        return true;    }    // adding employee to list failed    return false; } bool Company::AddEmployee(uint id, const string &name, double salary,        uint managerId) {    // create employee object    Employee emp(id,name,salary,managerId);    // call this class's overloaded AddEmployee function, and return status    return AddEmployee(emp); } int Company::FindById(uint empid) {    // init pos value    int pos = 0;    // init current node as head    Node * currNode = _head;    while(currNode != NULL)    {        // increment position counter        pos++;        // if current nodes data matches empid        if(currNode->data->getId() == empid)        {            // return pos value            return pos;        }        // point to next node in list        currNode = currNode->next;    }    // return not found indicator value    return -1; } int Company::FindByIdBinarySearch(uint empid) {    // init pos value    int start = 1, end = _size;    int pivot;    uint id;    // init current node as head    Employee * emp;    while(start <= end)    {        // calculate pivot        pivot = (start + end)/2;        if(start > end)        {            break;        }        emp = Get(pivot);        // get ID        id = emp->getId();        // if current nodes ID matches empid        if(id == empid)        {            // return pos value            return pivot;        }        else if(empid > id)        {            // set start as pivot + 1            start = pivot + 1;        }        else        {            // set end as pivot -1            end = pivot - 1;        }    }    // return not found indicator value    return -1; } int Company::FindByName(const string &name, uint startPos) {    // init pos value    uint pos;    // init current node as head    Node * currNode = _head;    // check if there are enough employees    if(startPos <= _size && startPos > 0)    {        pos = 1;        // move to startpos        while(currNode != NULL && pos < startPos)        {            // skipping nodes till startpos            currNode = currNode->next;            // increament skip count            pos++;        }        while(currNode != NULL)        {            // if current nodes data matches empid            if(currNode->data->getName() == name)            {                // return pos                return pos;            }            // increment position counter            pos++;            // point to next node in list            currNode = currNode->next;        }    }    // return not found pos value    return -1; } int Company::Read(istream &in) {    uint empID, mID;    string name;    int count = 0;    double salary;    while(in >> empID)    {        in >> name >> salary >> mID;        this->AddEmployee(empID,name,salary,mID);        count++;    }    return count>0?count:-1; } int Company::Write(ostream &out) {    int count = 0;    Node * empNode = _head;    while(empNode!=NULL)    {        Employee *emp = empNode->data;        // write employee data        out<<emp->getId()<<" ";        out<<emp->getName()<<" ";        out<<fixed<<setprecision(2)<<emp->getSalary()<<" ";        out<<emp->getManagerId()<<endl;        // increment written count        count++;        // get next node in list        empNode = empNode->next;    }    return count>0?count:-1; } bool Company::IsFull() {    return false; } Employee* Company::Get(uint pos) {    // init current node as head    Node * currNode = NULL;    uint currPos = 1;    // check if there are enough employees    if(pos <= _size && pos > 0)    {        currNode = _head;        // move to startpos        while(currNode != NULL && pos != currPos )        {            // skipping nodes till startpos            currNode = currNode->next;            // increment currPos counter            currPos++;        }        // if node found        if(currNode != NULL)        {            // return employee object            return currNode->data;        }    }    // if no such position in the list    return NULL; } uint Company::GetEmployeeCount() {    // return employee count    return _size; }

Company.h #ifndef COMPANY_H_ #define COMPANY_H_ #include "Employee.h" class Company { private:    struct Node{Employee *data;    Node *next;    };    Node* _head;    uint _size; public:    Company();    virtual ~Company();    Company(const Company &other);    bool AddEmployee(const Employee&);    bool AddEmployee(uint, const string &,double, uint=0);    int FindById(uint);    int FindByIdBinarySearch(uint);    int FindByName(const string&, uint);    int Read(istream &);    int Write(ostream &);    bool IsFull();    Employee* Get(uint);    uint GetEmployeeCount(); }; #endif /* COMPANY_H_ */

menu.cpp #include <iostream> #include <fstream> #include "Company.h" #include "Employee.h" using namespace std; void showMenu() {    cout<<endl;    cout<<"1. Load from File"<<endl;    cout<<"2. Save to File"<<endl;    cout<<"3. List all Employees"<<endl;    cout<<"4. Search by Name"<<endl;    cout<<"5. Search by ID"<<endl;    cout<<"6. Find Employee Boss Information"<<endl;    cout<<"7. Add new Employee"<<endl;    cout<<"8. Check if Database is Full"<<endl;    cout<<"9. Exit"<<endl; } int main() {    int choice, pos;    int recCount;    unsigned int empId;    bool isExit = false;    unsigned int empCount;    string fileName, nameToSearch;    string name;    double salary;    unsigned int id, mId;    ofstream out;    ifstream in;    Company company;    do    {        // display menu;        showMenu();        // read user choice and take action        // get user choice        cout<<endl<<"Enter your choice: ";        cin>>choice;        switch(choice)        {            case 1:                cout<<"Enter employee data file: ";                cin >>fileName;                // open file in read mode                in.open(fileName,ios::in);                if(in)                {                    recCount = company.Read(in);                    if(recCount > 0)                    {                        cout<<recCount<<" employee records loaded."<<endl;                    }                    else                    {                        cout<<"No record found in file"<<endl;                    }                }                else                {                    cout<<"Error reading file."<<endl;                }                // close stream                in.close();                break;            case 2:                cout<<"Where do you want to save the file: ";                cin >>fileName;                // open file in write mdoe                out.open(fileName,ios::out);                if(out)                {                    recCount = company.Write(out);                    if(recCount > 0)                    {                        cout<<recCount<<" employee records written to "<<fileName<<endl;                    }                }                else                {                    cout<<"Error writing file."<<endl;                }                // close stream                out.close();                break;            case 3:                empCount = company.GetEmployeeCount();                cout<<"Empcout "<<empCount<<endl;                // if employee count is 0                if(empCount==0)                {                    cout<<"No employees are there in company."<<endl;                }                else                {                    // for each employee int the list                    for(unsigned int i = 1; i <= empCount; i++)                    {                        // get employee at given position and print data on employee                        cout << company.Get(i)->ToString()<<endl;                    }                }                break;            case 4:                cout<<"Enter a name to search: ";                cin>>nameToSearch;                // start from position 1                pos = 0;                recCount = 0;                do                {                    // get position of employee with given name from a given start position                    pos = company.FindByName(nameToSearch,pos+1);                    // if position is valid                    if(pos > 0)                    {                        // get employee at given position and print data on employee                        cout << company.Get(pos)->ToString()<<endl;                        recCount++;                    }                }while(pos>0);                if(recCount == 0)                {                    cout<<"No employee with name '"<<nameToSearch<<"' found in database."<<endl;                }                break;            case 5:                cout<<"Enter employee ID to search: ";                cin>>empId;                // find position of employee                // sequential search //               pos = company.FindById(empId);                // binary search                pos = company.FindByIdBinarySearch(empId);                if(pos > 0)                {                    // get employee at given position and print data on employee                    cout << company.Get(pos)->ToString()<<endl;                }                else                {                    cout<<"Sorry. No employee with ID - "<<empId<<" found."<<endl;                }                break;            case 6:                cout<<"Enter employee ID to find the boss: ";                cin>>empId;                // find position of employee                pos = company.FindById(empId);                if(pos > 0)                {                    Employee * emp;                    // get employee at given position and print data on employee                    emp = company.Get(pos);                    cout << "Employee : "<< emp->ToString()<<endl;                    // get Manager's position                    pos = company.FindById(emp->getManagerId());                    if(pos > 0)                    {                        // get manager at given position and print data on manager                        cout <<"Manager : "<< company.Get(pos)->ToString()<<endl;                    }                    else                    {                        cout<<"Sorry. No manager with ID-"<<emp->getManagerId()<<" found."<<endl;                    }                }                else                {                    cout<<"Sorry. No employee with ID-"<<empId<<" found."<<endl;                }                break;            case 7:                cout<<"Enter employee name: ";                cin >>name;                cout<<"Enter employee ID: ";                cin >> id;                cout<<"Enter employee salary: ";                cin>> salary;                cout<< "Enter Manager's ID: ";                cin >> mId;                if(company.AddEmployee(id,name,salary,mId))                {                    cout<<"Employee added to database."<<endl;                }                break;            case 8:                if(company.IsFull())                {                    cout<<"Datbase is full."<<endl;                }                else                {                    cout<<"Database is not full."<<endl;                }                break;            case 9:                isExit = true;                break;            default:                cout<<"Invalid choice. Try again";        }    }while(!isExit);    return 0; }

Source Code Screenshots

Employee.h

Employee.cpp

Company.h

Company.cpp

menu.cpp

Output Screenshots