Basic operations in Linked List

I thought of sharing the code snippet. It just does the basic operations like inserting a node at the end of the linked list and deletion of any particular node in the linked list. The deletion of a node in linked list is based on the data of the node and not on the index at which data is located.

Code:

//Basic Linked list operation
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <string.h>

/*
 *
 * Program for single linked list which inserts / deletes
 * data into linked list. 
 *
 */

// Structure templates
struct list
{
	int no;
	struct list *shortlink;
};
typedef struct list node;

node *head = NULL;

void init(node*);
void InsertNode();
void DeleteNode();
void DisplayList();

void main()
{
	char ch = 'n';
	int opt;
	do
	{
		printf("\nEnter your option\n");
		printf("\n1. Insert a node\n");
		printf("\n2. Delete a particular node\n");
		printf("\n3. Display all the nodes\n");
		printf("\n4. Exit the application\n");
		scanf("%d",&opt);
		switch(opt)
		{
		case 1:
			InsertNode();
			DisplayList();
			break;
		case 2:
			DeleteNode();
			DisplayList();
			break;
		case 3:
			DisplayList();
			break;
		case 4:
			ch = 'y';
			break;
		}
	}while(ch != 'y');
	printf("\nDone by \"SHABBIR\"\n");
	getch();
}

void init(node *current)
{
	printf("\nEnter number\n");
	scanf("%d",&current->no);
	current->shortlink = NULL;
}

void InsertNode()
{
	node *newnode;
	
	newnode=(node*)malloc(sizeof(node));

	init(newnode);

	if(head == NULL)
	{
		head = newnode;
	}
	else
	{
		node *current = head;

		// Move to the end of the linked list
		while(current->shortlink!=NULL)
		{
			current=current->shortlink;
		}
		if(current->shortlink==NULL)
		{
			newnode->shortlink = current->shortlink;
			current->shortlink = newnode;
		}
	}
}

void DeleteNode()
{
	node* current = head;
	int rno;
	node *newnode,*temp;

	printf("\nEnter the number whose node you want to delete\n");
	scanf("%d",&rno);
	newnode=current;

	if(current->no==rno)
	{
		// Deleting the first node
		newnode=current;
		current=current->shortlink;
		free(newnode);
		head = current;
		return;
	}
	else
	{
		while(newnode->shortlink->shortlink!=NULL)
		{
			// Checking condition for deletion of
			// all nodes except first and last node
			if(newnode->shortlink->no==rno)
			{
				temp=newnode->shortlink;
				newnode->shortlink=newnode->shortlink->shortlink;
				free(temp);
				head = current;
				return;
			}
			newnode=newnode->shortlink;
		}
		if(newnode->shortlink->shortlink==NULL && newnode->shortlink->no==rno)
		{
			// Checking condition for deletion of last node
			free(newnode->shortlink);
			newnode->shortlink=NULL;
			head = current;
			return;
		}
	}
}

void DisplayList()
{
	node* current = head;

	while(current!=NULL)
	{
		printf("\n %d ",current->no);
		current=current->shortlink;
	}
}

You can improve on the code by making the DeleteNode function independent on data stored and making it based on which index needs deletion.

 

Thanks for counting.