Singularly Linked List Write the C function to insert a node

Singularly Linked List Write the C++ function to insert a node at the front/head of the singularly lists. Write the C++ function to delete a node. Assume the data in each node is an integer data value. Your function accepts two parameters, \'first\' and \'deleteltem\' (an integer value) and must delete the first node which has data equal to deleteItem\'. If the value of \'deleteItem\' is NOT in the Linked List, your code should display an appropriate message. Sample: 55 rightarrow 7 rightarrow 43 rightarrow NULL becomes 55 rightarrow 7 rightarrow 82 rightarrow 43 rightarrow NULL

Solution

// inserting items in the front or beginning of linkedlist

#include<iostream>

#include<conio.h>

#include<malloc.h>

using namespace std;

struct node

{

       int info;

       struct node *next;

}*start, *temp;

void insert_beg(int);

void display();

void main()

{

       start = NULL;

       int item, choice, location, element, position;

      

again:

       cout << \"\ Select the option \ 1.Insert values at Beginning of the linked list \ 2.Display Linked list \ 3.Exit Program\ \";

       cout << \"Enter Choice : \";

       cin >> choice;

       switch (choice)

       {

       case 1:cout << \"Enter item to insert : \";

              cin >> item;

              insert_beg(item);

              goto again;

       case 2:cout << \"\ Inserted item = \";

              display();

              goto again;

       case 3: exit(0);

       default:break;

       }

       getch();

}

void insert_beg(int item)

{

       temp = (node*)malloc(sizeof(node));

       temp->info = item;

       temp->next = start;

       start = temp;

}

void display()

{

       temp = start;

       while (temp != NULL)

       {

              cout << temp->info << \" \";

              temp = temp->next;

       }

       cout << \"\ \";

}

// Program for deletion

#include<iostream>

#include<conio.h>

#include<malloc.h>

using namespace std;

struct node

{

       int info;

       struct node *next;

}*start, *temp;

void insert_beg(int);

void display();

void deleteNode(struct node *, int);

void delete_beg();

void main()

{

       start = NULL;

       int item, choice, location, element, position;

again:

       cout << \"\ Select the option \ 1.Insert values at Beginning of the linked list \ 2.Display Linked list \ 3.Delete Node \ 4.Exit Program\ \";

       cout << \"Enter Choice : \";

       cin >> choice;

       switch (choice)

       {

       case 1:cout << \"Enter item to insert : \";

              cin >> item;

              insert_beg(item);

              goto again;

       case 2:cout << \"\ Inserted item = \";

              display();

              goto again;

       case 3:cout << \"Enter item to delete : \";

              cin >> item;

              deleteNode(start, item);

              goto again;

       case 4: exit(0);

       default:break;

       }

       getch();

}

void insert_beg(int item)

{

       temp = (node*)malloc(sizeof(node));

       temp->info = item;

       temp->next = start;

       start = temp;

}

void display()

{

       temp = start;

       while (temp != NULL)

       {

              cout << temp->info << \" \";

              temp = temp->next;

       }

       cout << \"\ \";

}

void deleteNode(struct node *head, int deleteItem)

{

       struct node *ptr, *preptr;

       ptr = start;

       preptr = start;

       if (ptr->info == deleteItem)

       {

              delete_beg();

       }

       else

       {

              while (ptr->info != deleteItem)

              {

                     preptr = ptr;

                     ptr = ptr->next;

              }

              preptr->next = ptr->next;

              free(ptr);

       }

}

void delete_beg()

{

       struct node *ptr;

       ptr = start;

       start = start->next;

       free(ptr);

}