Searching in Linked List

Sequential search is the most common search used on linked list structures.

Algorithm

Step-1: Initialise the Current pointer with the beginning of the List.

Step-2: Compare the KEY value with the Current node value; 

			if they match then quit there  

			else go to step-3.

Step-3: Move the Current pointer to point to the next node in the list and go to step-2, till the list is not over or else quit.

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Example

/*Search An Element in Linked List*/

#include<stdio.h>

#include<conio.h>

#include<malloc.h>

struct node

{

  int data;

  struct node *next;

}

first, *nw;

int search(int);

void main()

{

	int no,i,item,pos;

	clrscr();

	first.next=NULL;

	nw=&first;

	printf("Enter The No of nodes, you want in linked list: ");

	scanf("%d",&no);

	printf("\n");

	for(i=0;i< no;i++)

	{

		nw->next=(struct node *)malloc(sizeof(struct node));

		printf("Enter element in node %d: ",i+1);

		scanf("%d",&nw->data);

		nw=nw->next;

	}

	nw->next=NULL;

	printf("Linked list is:\n");

	nw=&first;

	while(nw->next!=NULL)

	{

		printf("%d\t",nw->data);

		nw=nw->next;

	}

	printf("\n");

	printf("Enter item to be searched : ");

	scanf("%d",&item);

	pos=search(item);

	if(pos<=no)

		printf("Your item is at node=%d",pos);

	else

		printf("Sorry! your item is not in linked list.");

	getch();

}



int search(int item)

{

	int count=1;

	nw=&first;

	while(nw->next!=NULL)

	{

		if(nw->data==item)

			break;

		else

			count++;

			nw=nw->next;

	}

	return count;

}

Output

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