Linked List Example

A Sample LinkedList implementation in c++ is demonstrated below. The list maintains persons records with age and name.

	struct Person{
	int id;
	string name;
	Person *next;
	};
	struct List{
	Person *head;
	};
	[/sourcecode]
	All the operations of the linkedlist are here:
	[sourcecode language="cpp"]
	#include<iostream>
	#include<string>
	#include<conio.h>
	using namespace std;
	struct Person{
	int id;
	string name;
	Person *next;
	};
	struct List{
	Person *head;
	};
	//initialize linked list
	void Initialize(List *personlist);
	// Insert node in front of linked list
	void InsertFront(List *personlist);
	// Insert node at the rear of linked list
	void InsertRear(List *personlist);
	// Delete node from front of linked list
	void DeleteFront(List *personlist);
	void DeleteRear(List *personlist);
	// Delete a node from any position of linked list
	void DeleteAny(List *personlist);
	// Searching in linked list
	void SearchPerson(List *personlist);
	void PrintList(List *personlist);
	//Deleting all nodes in linked list
	void EmptyList(List *personlist);
	// Reversing linked list
	void Reverse(List *personlist);
	//sorting linked list
	void SortPersons(List *personlist);
	int main()
	{
	List *personlist = NULL;
	personlist = new List;
	Initialize(personlist);
	int choice = 0;
	do
	{
	cout<<endl<<endl<<"\t\t Press"<<endl;
	cout << "\t\t [1] key To Add person in front" << endl;
	cout << "\t\t [2] key To Add person in rear" << endl;
	cout << "\t\t [3] key To Delete person from front" << endl;
	cout << "\t\t [4] key To Delete person from rear" << endl;
	cout << "\t\t [5] key To Print person List" << endl;
	cout << "\t\t [6] key To Reverse person List" << endl;
	cout << "\t\t [7] key To Delete all persons" << endl;
	cout << "\t\t [8] key To Delete a person by Id" << endl;
	cout << "\t\t [9] key To Search" << endl;
	cout << "\t\t [10] key To Sort Persons" << endl;
	cout << "\t\t [11] key To Exit" << endl;
	cout << "\t\t ";cin >> choice;
	switch (choice)
	{
	case 1:
	InsertFront(personlist);
	PrintList(personlist);
	break;
	case 2:
	InsertRear(personlist);
	PrintList(personlist);
	break;
	case 3:
	DeleteFront(personlist);
	break;
	case 4:
	DeleteRear(personlist);
	break;
	case 5:
	PrintList(personlist);
	break;
	case 6:
	Reverse(personlist);
	break;
	case 7:
	EmptyList(personlist);
	break;
	case 8:
	DeleteAny(personlist);
	break;
	case 9:
	SearchPerson(personlist);
	break;
	case 10:
	SortPersons(personlist);
	break;
	case 11:
	exit(0);
	break;
	default:
	cout<<"Wrong choice"<<endl;
	break;
	}
	}
	while(true);
	}
	void Initialize(List *person)
	{
	person->head = NULL;
	}
	void PrintList(List *personlist)
	{
	Person * temp;
	temp = personlist->head;
	cout <<endl<<"Total Persons in the list: "<<endl;
	cout<<"------------------------------------------------"<<endl;
	int i = 0;
	if (temp == NULL)
	{
	cout<<"List is empty"<<endl;
	cout<<"------------------------------------------------"<<endl;
	}
	while (temp != NULL)
	{
	i++;
	cout <<"P"<<i<<")\t Id: "<< temp->id <<" - Name: "<< temp->name<<endl;
	temp = temp->next;
	cout<<"------------------------------------------------"<<endl;
	}
	}
	void Reverse(List *personlist)
	{
	cout<<"------------------------------------------------"<<endl;
	if (personlist->head == NULL)
	{
	cout<<"Sorry: Person list is empty"<<endl;
	cout<<"------------------------------------------------"<<endl;
	return;
	}
	Person *person = personlist->head;
	Person *person_n;
	Person *temp;
	temp = person;
	person = person->next;
	person_n = person;
	while (person_n->next != NULL)
	{
	person_n = person_n->next;
	person->next = temp;
	temp = person;
	person = person_n;
	}
	person_n->next = temp;
	Person *person1 = personlist->head;
	person1->next = NULL;
	personlist->head = person_n;
	}
	void InsertFront(List *personlist)
	{
	int id;
	string name;
	cout <<"Entere id: ";
	cin >> id;
	cout <<"Entere Name: ";
	cin >> name;
	Person *newPerson = new Person();
	newPerson->id = id;
	newPerson->name = name;
	if (personlist->head == NULL)
	{
	personlist->head = newPerson;
	newPerson->next = NULL;
	}
	else
	{
	newPerson->next = personlist->head;
	personlist->head = newPerson;
	}
	}
	void InsertRear(List *personlist)
	{
	int id;
	string name;
	cout <<"Enter id: ";
	cin >> id;
	cout <<"Enter Name: ";
	cin >> name;
	Person *newPerson = new Person();
	newPerson->id = id;
	newPerson->name = name;
	if (personlist->head == NULL)
	{
	personlist->head = newPerson;
	newPerson->next = NULL;
	}
	else
	{
	Person *temp = personlist->head;
	while (temp->next != NULL)
	{
	temp = temp->next;
	}
	temp->next = newPerson;
	newPerson->next = NULL;
	}
	}
	void DeleteFront(List *personlist)
	{
	cout<<"------------------------------------------------"<<endl;
	if (personlist->head == NULL)
	{
	cout<<"Sorry: Person list is empty"<<endl;
	cout<<"------------------------------------------------"<<endl;
	}
	else
	{
	Person *person = personlist->head;
	if (person->next == NULL)
	{
	delete person;
	personlist->head = NULL;
	}
	else
	{
	personlist->head = person->next;
	delete person;
	}
	cout<<"Success: Person is deleted"<<endl;
	cout<<"------------------------------------------------"<<endl;
	}
	}
	void DeleteRear(List *personlist)
	{
	cout<<"------------------------------------------------"<<endl;
	if (personlist->head == NULL)
	{
	cout<<"Sorry: Person list is empty"<<endl;
	cout<<"------------------------------------------------"<<endl;
	}
	else
	{
	Person *person = personlist->head;
	if (person->next == NULL)
	{
	delete person;
	personlist->head = NULL;
	}
	else
	{
	Person *tmp = person;
	while (person->next != NULL)
	{
	tmp = person;
	person = person->next;
	}
	delete person;
	tmp->next = NULL;
	}
	cout<<"Success: Person is deleted"<<endl;
	cout<<"------------------------------------------------"<<endl;
	}
	}
	void DeleteAny(List *personlist)
	{
	cout<<"------------------------------------------------"<<endl;
	if (personlist->head == NULL)
	{
	cout<<"Sorry: Person list is empty"<<endl;
	cout<<"------------------------------------------------"<<endl;
	}
	else
	{
	int ID;
	bool IsDel = false;
	cout <<"Enter person id to delete:\t";
	cin>>ID;
	Person *person = personlist->head;
	if (person->next == NULL)
	{
	if (person->id == ID)
	{
	delete person;
	personlist->head = NULL;
	IsDel = true;
	}
	else
	{
	IsDel = false;
	}
	}
	else if (person->next != NULL)
	{
	if (person->id == ID)
	{
	personlist->head = person->next;
	delete person;
	IsDel = true;
	}
	else
	{
	IsDel = false;
	}
	}
	if (!IsDel && person->next != NULL)
	{
	Person *tmp = person;
	person = person->next;
	while (person->next != NULL)
	{
	if (person->id == ID)
	{
	tmp->next = person->next;
	delete person;
	IsDel = true;
	break;
	}
	tmp = person;
	person = person->next;
	}
	if (person->id == ID)
	{
	delete person;
	tmp->next = NULL;
	IsDel = true;
	}
	}
	if (IsDel)
	{
	cout<<"Success: Person is deleted"<<endl;
	}
	else
	{
	cout<<"Sorry: Could not find person"<<endl;
	}
	cout<<"------------------------------------------------"<<endl;
	}
	}
	void EmptyList(List *personlist)
	{
	cout<<"------------------------------------------------"<<endl;
	if (personlist->head == NULL)
	{
	cout<<"Sorry: Person list is empty"<<endl;
	cout<<"------------------------------------------------"<<endl;
	}
	else
	{
	Person *person = personlist->head;
	if (person->next == NULL)
	{
	delete person;
	personlist->head = NULL;
	}
	else
	{
	Person *tmp = person;
	while (person->next != NULL)
	{
	tmp = person;
	person = person->next;
	delete tmp;
	}
	personlist->head = NULL;
	}
	cout<<"Success: List is deleted"<<endl;
	cout<<"------------------------------------------------"<<endl;
	}
	}
	void SearchPerson(List *personlist)
	{
	cout<<"------------------------------------------------"<<endl;
	if (personlist->head == NULL)
	{
	cout<<"Sorry: Person list is empty"<<endl;
	cout<<"------------------------------------------------"<<endl;
	return;
	}
	int ID;
	bool IsFound = false;
	cout <<"Enter ID of the person to search:";
	cin>> ID;
	Person *person = personlist->head;
	if (person->next == NULL)
	{
	if (person->id == ID)
	{
	cout <<"Person Found:"<<endl;
	cout<<person->name<<endl;
	IsFound = true;
	}
	else
	{
	IsFound = false;
	}
	}
	else
	{
	while (person != NULL)
	{
	if (person->id == ID)
	{
	cout <<"Person Found:"<<endl;
	cout<<person->name<<endl;
	IsFound = true;
	break;
	}
	else
	{
	IsFound = false;
	}
	person = person->next;
	}
	if (!IsFound)
	{
	cout<<"Sorry: Person not found"<<endl;
	}
	}
	cout<<"------------------------------------------------"<<endl;
	}
	void SortPersons(List *personlist)
	{
	cout<<"------------------------------------------------"<<endl;
	if (personlist->head == NULL)
	{
	cout<<"Sorry: Person list is empty"<<endl;
	cout<<"------------------------------------------------"<<endl;
	return;
	}
	Person *person = personlist->head;
	if (person->next == NULL)
	{
	return;
	}
	Person *person_n = person;
	int temp_id;
	string temp_name;
	while (person != NULL)
	{
	person_n = person->next;
	while (person_n != NULL)
	{
	if (person->id < person_n->id )
	{
	temp_id = person->id;
	person->id = person_n->id;
	person_n->id = temp_id;
	temp_name = person->name;
	person->name = person_n->name;
	person_n->name = temp_name;
	}
	person_n = person_n->next;
	}
	person = person->next;
	}
	}

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