Program to remove duplicates from a sorted linked list.

#include<stdio.h>
#include<stdlib.h>
 
struct Node
{
    int data;
    struct Node* next;
};
 

void removeDuplicates(struct Node* head)
{
   
    struct Node* current = head;
 
   
    struct Node* next_next; 
   
   
    if (current == NULL) 
       return; 
 
   
    while (current->next != NULL) 
    {
      
       if (current->data == current->next->data) 
       {
                    
           next_next = current->next->next;
           free(current->next);
           current->next = next_next;  
       }
       else 
       {
          current = current->next; 
       }
    }
}
 

void push(struct Node** head_ref, int new_data)
{
    
    struct Node* new_node =
            (struct Node*) malloc(sizeof(struct Node));
             
   
    new_node->data  = new_data;
                 
        new_node->next = (*head_ref);     
         
  
    (*head_ref)    = new_node;
}
 

void printList(struct Node *node)
{
    while (node!=NULL)
    {
       printf("%d ", node->data);
       node = node->next;
    }
} 
 

int main()
{
    
    struct Node* head = NULL;
   
 
    push(&head, 20);
    push(&head, 13);
    push(&head, 13);  
    push(&head, 11);
    push(&head, 11);
    push(&head, 11);                                    
 
    printf("\n Linked list before duplicate removal  ");
    printList(head); 
 
   
    removeDuplicates(head); 
 
    printf("\n Linked list after duplicate removal ");         
    printList(head);            
   
    return 0;
}