Algorithm for Deletion at beginning of the list



DELETE AT BEG(INFO,NEXT,START)

1.IF(START=NULL)

2.ASSIGN PTR = STRAT 

3.ASSIGN TEMP = INFO[PTR]

4.ASSIGN START = NEXT[PTR]

5.FREE(PTR) 

6.RETURN(TEMP)







Fuction of Deletion at the front of Linked list



void deleteatbeg(node **start)

{ 

	node *ptr;

	int temp;

	ptr = *start ;

	temp = ptr->info;

	*start = ptr->next ;

	free(ptr);

	printf("\nDeleted item is %d : \n",temp);

}



Deletion at the front of Linked list



#include<stdio.h>

#include<conio.h>

#include<malloc.h>

typedef struct nodetype

{ 

	int info;

	struct nodetype *next;

} node ;

void createlist(node **,int );

void deleteatbeg(node **);

void display(node *);

void main()

{

	node *start;

	int item,n,i;

	start=NULL;

	clrscr();

	printf("Enter no. of nodes :\n");

	scanf("%d",&n);

	for(i= 0 ;i< n ;i++)

	{	 

		printf("Item for node %d :\n",i+1);

		scanf("%d",&item);

		createlist(&start,item) ;

	}

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

	display(start);

	printf("\nPress any key to delete first node");

	getch();

	deleteatbeg(&start);

	printf("\nThe list after the deletion at first is :\n");

	display(start);

	getch();

}

void createlist(node **start,int item)

{ 

	node *ptr,*last;

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

	ptr->info = item ;

	ptr->next = NULL;

	if(*start == NULL)

	*start = ptr ;

	else

	{ 

		last = *start ;

		while(last->next !=NULL)

		{  

			last = last->next;

		}

		last->next = ptr ;

	}

}

void deleteatbeg(node **start)

{ 

	node *ptr;

	int temp;

	ptr = *start ;

	temp = ptr->info;

	*start = ptr->next ;

	free(ptr);

	printf("\nDeleted item is %d : \n",temp);

}

void display(node *start)

{   int n = 0;

	while(start !=NULL)

    { 

		printf("\t %d",start->info);

		n++;

		start = start->next;

    }

     printf("\n Total number of nodes : %d",n);

}



Output



Quantitative Aptitude
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Programming
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