4.Data.structures

#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <iostream>
#include <conio.h>
using namespace std;

enum Sex
{
    Female,
    Male
};

struct Person {
    string Name;
    string Surname;
    Sex Sex;
    unsigned int Age;
};

Person ReadPerson() {
    Person person;
    cout << "\nName:\n";
    cin >> person.Name;
    cout << "Surname:\n";
    cin >> person.Surname;
    while (1)
    {
        cout << "Enter Sex(M or F)" << endl;
        char sex;
        sex = _getch();
        if ((sex == 'M') || (sex == 'm'))
        {
            person.Sex = Male;
            cout << "Male\n";
            break;
        }
        else
        {
            if ((sex == 'F') || (sex == 'f'))
            {
                person.Sex = Female;
                cout << "Female\n";
                break;
            }
        }
        {
            cout << "Incorrect" << endl;
        }
    };
    cout << "Age:\n";
    cin >> person.Age;
    return person;
}

struct Node
{
    Person Person;
    Node* NextItem;
    Node* PrevItem;
};

struct List
{
    Node* Head = NULL;
    Node* Tail = NULL;
};

bool CheckList(List List)
{
    return List.Head;
};

void Add(List &List)
{
    Node *temp = new Node;
    temp->Person = ReadPerson();
    temp->NextItem = NULL;
    if (CheckList(List) == NULL)
    {
        List.Head = temp;
        temp->PrevItem = NULL;
        cout << "Created head\n";
    }
    else
    {
        List.Tail->NextItem = temp;
        temp->PrevItem = List.Tail;
        cout << "Added tail\n";
    }
    List.Tail = temp;
    cout << "Person added\n";
}

void PrintPerson(Person person)
{
    cout << "\nName: " << person.Name << "\nSurname: " << person.Surname;
    switch (person.Sex)
    {
    case(Male) : cout << "\nSex: Male" << endl; break;
    case(Female) : cout << "\nSex: Female" << endl; break;
    }
    cout << "Age: " << person.Age << "\n\n";
}

void Show(List &List)
{
    Node* CurrentItem = List.Head;
    if (CheckList(List) == NULL)
    {
        cout << "\nList is empty!\n\n";
    }
    else
    {
        while (CurrentItem != NULL)
        {
            PrintPerson(CurrentItem->Person);
            CurrentItem = CurrentItem->NextItem;
        }
    }
}

int GetLen(List &List)
{
    Node *temp = List.Head;
    int i = 0;
    while (temp)
    {
        i++;
        temp = temp->NextItem;
    }
    return i;
}

Node* Get(int index, List &List)
{
    int count = GetLen(List);
    if (index > count)
    {
        cout << "\nNo element\n\n";
        return NULL;
    };
    /////
    int i = index;
    if (i > -1)
    {
        Node* CurrentItem = List.Head;
        while ((i != 0) && (CurrentItem != NULL))
        {
            i--;
            CurrentItem = CurrentItem->NextItem;
        }
        if ((i == 0) && (CurrentItem != NULL))
            return CurrentItem;
    }
    return NULL;
}

void Remove(int index, List &List)
{
    int count = GetLen(List);
    int i = index;
    if (index > count)
    {
        cout << "\nNo element\n\n";
    }
    else if (i > -1)
    {
        Node* CurrentItem = List.Head;
        if (i == 0)
        {
            List.Head = List.Head->NextItem;
            List.Head->PrevItem = NULL;
            delete CurrentItem;
        }
        else
        {
            while ((i != 0) && (CurrentItem != NULL))
            {
                i--;
                CurrentItem = CurrentItem->NextItem;
            }
            if ((i == 0) && (CurrentItem->NextItem != NULL))
            {
                CurrentItem->PrevItem->NextItem = CurrentItem->NextItem;
                CurrentItem->NextItem->PrevItem = CurrentItem->PrevItem;
                delete CurrentItem;
            }
            if ((i == 0) && (CurrentItem->NextItem == NULL) && (CurrentItem != NULL))
            {
                List.Tail = List.Tail->PrevItem;
                List.Tail->NextItem = NULL;
                delete CurrentItem;
            }
        }
    }
}

void Insert(int index, List &List)
{

    int count = GetLen(List);
    int i = index;
    if (index > count)
    {
        cout << "\nNo element\n\n";
    }
    else if (i > -1)
    {
        if (CheckList(List))
        {
            Node* temp = new Node;
            if (i == 0)
            {
                temp->Person = ReadPerson();
                List.Head->PrevItem = temp;
                temp->NextItem = List.Head;
                List.Head = temp;
            }
            else
            {
                Node* CurrentItem = List.Head;
                while ((i != 0) && (temp != NULL))
                {
                    i--;
                    CurrentItem = CurrentItem->NextItem;
                }
                if ((i == 0) && (CurrentItem->NextItem != NULL))
                {
                    temp->Person = ReadPerson();
                    temp->PrevItem = CurrentItem;
                    temp->NextItem = CurrentItem->NextItem;
                    CurrentItem->PrevItem->NextItem = temp;
                    CurrentItem->NextItem->PrevItem = temp;
                }
                if ((i == 0) && (CurrentItem->NextItem == NULL) && (CurrentItem != NULL))
                {
                    temp->Person = ReadPerson();
                    List.Tail->NextItem = temp;
                    temp->PrevItem = List.Tail;
                    List.Tail = temp;
                }
                else
                    cout << "Not possible.\n";
            }
        }
        else
            Add(List);
    }
}

void Clear(List List)
{
    while (List.Head != NULL)
    {
        cout << "Clearing\n";
        Node* CurrentItem = List.Head;
        if (List.Head->NextItem != NULL)
        {
            List.Head->NextItem->PrevItem = NULL;
            List.Head->NextItem = List.Head;
        }
        else
            List.Head = NULL;
        delete CurrentItem;
    }
    cout << "Cleared\n";

}

void MainMenu()
{
    cout << "\t--------------------------------------\n"
        << "\t------List of Person : Main Menu------\n"
        << "\t1. Add Person\n\t2. Insert Person\n\t3. Get Person By Index\n"
        << "\t4. Remove Person By Index\n\t5. Show All Persons\n"
        << "\t6. Clear List\n\n\tChoose action(1 - 6):";
}

int main()
{
    int n = 1;
    int i;
    char buffer[256];
    List list;

    while (n != 6)
    {
        MainMenu();
        cin >> buffer;
        n = atoi(buffer);
        switch (n)
        {
        case 1:
            Add(list);
            break;
        case 2:
            cout << "Enter the index: ";
            cin >> i;
            Insert(i, list);
            break;
        case 3:
            cout << "Enter the index: ";
            cin >> i;
            if (Get(i, list) != NULL)
                PrintPerson((Get(i, list))->Person);
            break;
        case 4:
            cout << "Enter the index: ";
            cin >> i;
            if (Get(i, list) != NULL)
                Remove(i, list);
            else
                cout << "\nIncorrect input\n";
            break;
        case 5:
            cout << "List of persons currently in list:\n\n";
            Show(list);
            break;
        case 6:
            Clear(list);
            break;
        default:
            cout << "Incorrect number! Please try again\n";
        }
    }
    system("pause");
    return 0;
}