Last third element from end

 

#include<stdio.h>

#include<stdlib.h>

struct node

{

    int data;

    struct node *next;

};

struct node * head, *temp, *newnode, *temp2;

void create()

{   head=0;

    int choice=1;

    while(choice==1)

    {

       newnode=(struct node*)malloc(sizeof(struct node));

       newnode->next=0;

       printf("enter data : ");

       scanf("%d",&newnode->data);

       if(head==0)

       {

           head=newnode;

           temp=newnode;

       }

       else

        {

            temp->next=newnode;

            temp=newnode;

        }

        printf("Want another node: ");

        scanf("%d",&choice);

    }

 

}

void listprint()

{

    temp = head;

    while(temp!=0)

    {

        printf("%d ",temp->data);

        temp=temp->next;

    }

}

int main()

{

    printf("Create the list : \n");

    create();

    printf("The list is : \n");

    listprint();

    temp=head,temp2=head;

    if(head==0 || head->next==0 || head->next->next==0)

    printf("\n\nLast third element not present\n\n");

    else

    {

        //temp will be pointing to last position,

        //temp2 at last third position;

        temp=head;

        int i=1,pos=3;

        while(i<pos)

        {temp=temp->next;i++;}

        temp2=head;

        while(temp->next!=0)

        {

            temp=temp->next;

            temp2=temp2->next;

        }

printf("\n\nThe element at the last third position will be : %d\n",   temp2->data);

    }

}