Searching in singly linked list

Searching is performed in order to find the location of a particular element in the list. Searching any element in the list needs traversing through the list and make the comparison of every element of the list with the specified element. If the element is matched with any of the list element then the location of the element is returned from the function.

Algorithm

Step 1: SET PTR = HEAD
Step 2: Set I = 0
STEP 3: IF PTR = NULL

WRITE "EMPTY LIST"
GOTO STEP 8
END OF IF

STEP 4: REPEAT STEP 5 TO 7 UNTIL PTR != NULL
STEP 5: if ptr → data = item

write i+1
End of IF

STEP 6: I = I + 1
STEP 7: PTR = PTR → NEXT

[END OF LOOP]

STEP 8: EXIT

C function

	#include<stdio.h>
#include<stdlib.h>
void create(int);
void search();
struct node
{
	int data;
	struct node *next;
};
struct node *head;
void main ()
{
	int choice,item,loc;
	do 
	{
		printf("\n1.Create\n2.Search\n3.Exit\n4.Enter your choice?");
		scanf("%d",&choice);
		switch(choice)
		{
			case 1:
			printf("\nEnter the item\n");
			scanf("%d",&item);
			create(item);
			break; 
			case 2:
			search();
			case 3:
			exit(0);
			break;	
			default:
			printf("\nPlease enter valid choice\n");
		}
				
	}while(choice != 3);
}
	void create(int item)
	{
		struct node *ptr = (struct node *)malloc(sizeof(struct node *));
		if(ptr == NULL)
		{
			printf("\nOVERFLOW\n");
		}
		else
		{
			ptr->data = item;
			ptr->next = head;
			head = ptr;
			printf("\nNode inserted\n");
		}
		
	}
void search()
{
	struct node *ptr;
	int item,i=0,flag;
	ptr = head; 
	if(ptr == NULL)
	{
		printf("\nEmpty List\n");
	}
	else
	{ 
		printf("\nEnter item which you want to search?\n"); 
		scanf("%d",&item);
		while (ptr!=NULL)
		{
			if(ptr->data == item)
			{
				printf("item found at location %d ",i+1);
				flag=0;
			} 
			else
			{
				flag=1;
			}
			i++;
			ptr = ptr -> next;
		}
		if(flag==1)
		{
			printf("Item not found\n");
		}
	}	
		
}

Output

1.Create
2.Search
3.Exit
4.Enter your choice?1

Enter the item
23

Node inserted

1.Create
2.Search
3.Exit
4.Enter your choice?1

Enter the item
34

Node inserted

1.Create
2.Search
3.Exit
4.Enter your choice?2

Enter item which you want to search?
34
item found at location 1

Next Topic#

← prev next →