Insertion at the beginning of the Singly linked lists

Step 1. Create a new node and assign the address to any node say ptr.
Step 2. OVERFLOW,IF(PTR = NULL)
	   	write : OVERFLOW and EXIT.
Step 3. ASSIGN INFO[PTR] = ITEM
Step 4. IF(START = NULL) 
	    	ASSIGN NEXT[PTR] = NULL
       	 ELSE 
         	ASSIGN NEXT[PTR] = START
Step 5. ASSIGN START = PTR
Step 6. EXIT    




Insertion at the front of list

void insertion(struct node *nw)
{
	struct node start, *previous, *new1;
	nw = start.next;
	previous = &start;
	new1 = (struct node* ) malloc(sizeof(struct node));
	new1->next = nw ;
	previous->next = new1;
	printf("\n Input the fisrt node value: ");
	scanf("%d", &new1->data);
}





Insertion at the front of list

/* INSERT A NODE INTO A SIMPLE LINKED LIST AT THE BEGINNING */
# include <stdio.h>
# include <malloc.h>
# include <conio.h>

struct link
{
	int data;
	struct link *next;
};

int i;
int number;
struct link start, *previous, *new1;

void insertion(struct link *);
void create_list(struct link *);
void display(struct link *);

/* Function create a linked list */

void create_list(struct link *node)
{

	char ch;
	start.next = NULL;  
	node = &start;      /* Point to the start of the list */
	i = 0;
	fflush(stdin);
	printf("\n Input choice n for break: ");
	ch = getchar();
	while(ch != 'n')
	{
		node->next = (struct link* ) malloc(sizeof(struct link));
		node = node->next;
		printf("\n Input the node: %d: ", (i+1));
		scanf("%d", &node->data);
		node->next = NULL;
		fflush(stdin);
		printf("\n Input choice n for break: ");
		ch = getchar();
		i++;
	}
}

/* Inserting a node */

void insertion(struct link *node)
{
	node = start.next;

	previous = &start;

	new1 = (struct link* ) malloc(sizeof(struct link));
	new1->next = node ;
	previous->next = new1;
	printf("\n Input the fisrt node value: ");
	scanf("%d", &new1->data);
}

/* Display the list */

void display(struct link *node)
{
	node = start.next;
	printf("\n After Inserting a node list is as follows:\n");
	while (node)
	{
		printf(" %d\t", node->data);
		node = node->next;
	}
}

/* Function main */

void main()
{
	struct link *node = (struct link *) malloc(sizeof(struct link));
	clrscr();
	create_list(node);
	insertion(node);
	display(node);
    getch();
}



Output



Quantitative Aptitude
Reasoning
Programming
Interview