/*
Single Link List using C program
*/
#include <stdio.h>
#include <stdlib.h>
/* Structure of a node */
struct node
{
int item;
struct node *next;
} * head;
void createList(int n);
void displayList();
void insertNodeAtBeginning(int item);
void insertNodeAtEnd(int item);
void insertNodeAtMiddle(int item, int position);
void deleteFirstNode();
void deleteLastNode();
void deleteMiddleNode(int position);
int main()
{
int n, item, position;
int choice;
for (;;)
{
printf("\n===========::Single Link List Menu::=================\n\n ");
printf("\n1. Press 1 for Creating Lists\n");
printf("\n2. Press 2 for display Lists\n");
printf("\n3. Press 3 for insert item into fisrt Position of Lists\n");
printf("\n4. Press 4 for insert item into last Position of Lists\n");
printf("\n5. Press 5 for insert item into specified middle Position of Lists\n");
printf("\n6. Press 6 for delete item from fisrt Position of Lists\n");
printf("\n7. Press 7 for delete item from last Position of Lists\n");
printf("\n8. Press 8 for delete item from specified middle Position of Lists\n");
printf("\n===========::Single Link List Menu::=================\n ");
printf("\n\tEnter your choice:");
scanf("%d", &choice);
switch (choice)
{
case 1:
printf("Enter the total number of nodes: ");
scanf("%d", &n);
createList(n);
break;
case 2:
printf("\nitem in the list \n");
displayList();
break;
case 3:
printf("\nEnter item to insert at beginning of the list: ");
scanf("%d", &item);
insertNodeAtBeginning(item);
break;
case 4:
printf("\nEnter item to insert at end of the list: ");
scanf("%d", &item);
insertNodeAtEnd(item);
break;
case 5:
printf("nEnter item to insert at middle of the list: ");
scanf("%d", &item);
printf("Enter the position to insert new node: ");
scanf("%d", &position);
insertNodeAtMiddle(item, position);
break;
case 6:
deleteFirstNode();
break;
case 7:
deleteLastNode();
break;
case 8:
printf("\nEnter the node position you want to delete: ");
scanf("%d", &position);
deleteMiddleNode(position);
break;
case 9:
exit(1);
break;
default:
printf("Wrong selction");
}
}
return 0;
}
void createList(int n)
{
struct node *newNode, *temp;
int item, i;
head = (struct node *)malloc(sizeof(struct node));
if (head == NULL)
{
printf("Unable to allocate memory.");
exit(0);
}
printf("Enter the item of node 1: ");
scanf("%d", &item);
head->item = item;
head->next = NULL;
temp = head;
for (i = 2; i <= n; i++)
{
newNode = (struct node *)malloc(sizeof(struct node));
if (newNode == NULL)
{
printf("Unable to allocate memory.");
break;
}
printf("Enter the item of node %d: ", i);
scanf("%d", &item);
newNode->item = item;
newNode->next = NULL;
temp->next = newNode;
temp = temp->next;
}
}
void displayList()
{
struct node *temp;
if (head == NULL)
{
printf("List is empty.");
}
else
{
temp = head;
while (temp != NULL)
{
printf("item = %d\n", temp->item);
temp = temp->next;
}
}
}
void insertNodeAtBeginning(int item)
{
struct node *newNode;
newNode = (struct node *)malloc(sizeof(struct node));
if (newNode == NULL)
{
printf("Unable to allocate memory.");
}
else
{
newNode->item = item;
newNode->next = head;
head = newNode;
printf("item INSERTED SUCCESSFULLY\n");
}
}
void insertNodeAtEnd(int item)
{
struct node *newNode, *temp;
newNode = (struct node *)malloc(sizeof(struct node));
if (newNode == NULL)
{
printf("Unable to allocate memory.");
}
else
{
newNode->item = item;
newNode->next = NULL;
temp = head;
while (temp != NULL && temp->next != NULL)
temp = temp->next;
temp->next = newNode;
printf("item INSERTED SUCCESSFULLY\n");
}
}
void insertNodeAtMiddle(int item, int position)
{
int i;
struct node *newNode, *temp;
newNode = (struct node *)malloc(sizeof(struct node));
if (newNode == NULL)
{
printf("Unable to allocate memory.");
}
else
{
newNode->item = item;
newNode->next = NULL;
temp = head;
for (i = 2; i <= position - 1; i++)
{
temp = temp->next;
if (temp == NULL)
break;
}
if (temp != NULL)
{
newNode->next = temp->next;
temp->next = newNode;
printf("item INSERTED SUCCESSFULLY\n");
}
else
{
printf("UNABLE TO INSERT item AT THE GIVEN POSITION\n");
}
}
}
void deleteFirstNode()
{
struct node *toDelete;
if (head == NULL)
{
printf("List is already empty.");
}
else
{
toDelete = head;
head = head->next;
printf("\nData deleted = %d\n", toDelete->item);
free(toDelete);
printf("Successfully Delete First Node\n");
}
}
void deleteLastNode()
{
struct node *toDelete, *secondLastNode;
if (head == NULL)
{
printf("List is already empty.");
}
else
{
toDelete = head;
secondLastNode = head;
while (toDelete->next != NULL)
{
secondLastNode = toDelete;
toDelete = toDelete->next;
}
if (toDelete == head)
{
head = NULL;
}
else
{
secondLastNode->next = NULL;
}
free(toDelete);
printf("Successfully Deleted Last Node\n");
}
}
void deleteMiddleNode(int position)
{
int i;
struct node *toDelete, *prevNode;
if (head == NULL)
{
printf("List is already empty.");
}
else
{
toDelete = head;
prevNode = head;
for (i = 2; i <= position; i++)
{
prevNode = toDelete;
toDelete = toDelete->next;
if (toDelete == NULL)
break;
}
if (toDelete != NULL)
{
if (toDelete == head)
head = head->next;
prevNode->next = toDelete->next;
toDelete->next = NULL;
free(toDelete);
printf("Successfully\n");
}
else
{
printf("Invalid position unable to delete.");
}
}
}
