Add a new node to the ascending order linked list.

• C Program to add a new node to the ascending order linked list.

#include <stdio.h>
#include <conio.h>
#include <alloc.h>

/* structure containing a data part and link part */
struct node
{
    int data ;
    struct node *link ;
} ;

void add ( struct node **, int ) ;
void display ( struct node * ) ;
int count ( struct node * ) ;
void delete ( struct node **, int ) ;

void main( )
{
    struct node *p ;
    p = NULL ;  /* empty linked list */

    add ( &p, 5 ) ;
    add ( &p, 1 ) ;
    add ( &p, 6 ) ;
    add ( &p, 4 ) ;
    add ( &p, 7 ) ;

    clrscr( ) ;
    display ( p ) ;
    printf ( "\nNo. of elements in Linked List = %d", count ( p ) ) ;
}

/* adds node to an ascending order linked list */
void add ( struct node **q, int num )
{
    struct node *r, *temp = *q ;

    r = malloc ( sizeof ( struct node ) ) ;
    r -> data = num ;

    /* if list is empty or if new node is to be inserted before the first node */
    if ( *q == NULL || ( *q ) -> data > num )
    {
        *q = r ;
        ( *q ) -> link = temp ;
    }
    else
    {
        /* traverse the entire linked list to search the position to insert the
            new node */
        while ( temp != NULL )
        {
            if ( temp -> data <= num && ( temp -> link -> data > num ||
                                        temp -> link == NULL ))
            {
                r -> link = temp -> link ;
                temp -> link = r ;
                return ;
            }
            temp = temp -> link ;  /* go to the next node */
        }
    }
}

/* displays the contents of the linked list */
void display ( struct node *q )
{
    printf ( "\n" ) ;

    /* traverse the entire linked list */
    while ( q != NULL )
    {
        printf ( "%d ", q -> data ) ;
        q = q -> link ;
    }
}

/* counts the number of nodes present in the linked list */
int count ( struct node *q )
{
    int c = 0 ;

    /* traverse the entire linked list */
    while ( q != NULL )
    {
        q = q -> link ;
        c++ ;
    }
    return c ;
}