middleOfLL.cpp

#include<stdio.h>
#include<stdlib.h>
 
/* Link list node */
struct Node
{
    int data;
    struct Node* next;
};
 
/* Function to get the middle of the linked list*/
void printMiddle(struct Node *head)
{
    struct Node *temp = head;
    int count = 0;
    while(temp != NULL)
    {
        count++;
        temp = temp->next;
    }
    temp = head;
    int i = 0;
    while(i < count/2)
        {
            i++;
            temp = temp->next;
        }
    printf("middle :%d\n",temp->data);
}
 
void push(struct Node** head_ref, int new_data)
{
    /* allocate node */
    struct Node* new_node =
        (struct Node*) malloc(sizeof(struct Node));
 
    /* put in the data  */
    new_node->data  = new_data;
 
    /* link the old list off the new node */
    new_node->next = (*head_ref);
 
    /* move the head to point to the new node */
    (*head_ref)    = new_node;
}
 
// A utility function to print a given linked list
void printList(struct Node *ptr)
{
    while (ptr != NULL)
    {
        printf("%d->", ptr->data);
        ptr = ptr->next;
    }
    printf("NULL\n");
}
 
/* Drier program to test above function*/
int main()
{
    /* Start with the empty list */
    struct Node* head = NULL;
    int i;
 
    for (i=5; i>0; i--)
    {
        push(&head, i);
        printList(head);
        printMiddle(head);
    }
 
    return 0;
}