My solution in C#: easiest solution

static SinglyLinkedListNode removeDuplicates(SinglyLinkedListNode llist) { SinglyLinkedListNode currNode = llist;

    while(currNode !=null && currNode.next!= null)
    {
        if(currNode.data==currNode.next.data)
        {
            currNode.next = currNode.next.next;
        }
        else 
        currNode = currNode.next;

    }
    return llist;
}