Implement an algorithm to find the nth to last element of a singly linked list.

__author__ = 'nitin'

class Node:
    def __init__(self,initdata):
        self.data=initdata
        self.next=None
    def getData(self):
        return self.data
    def setData(self,item):
        self.data=item
    def getNext(self):
        return self.next
    def setNext(self,item):
        self.next=item

class UnorderedList:
    def __init__(self):
        self.head=None

    def isEmpty(self):
        return self.head==None

    def add(self,item):
        temp=Node(item)
        temp.setNext(self.head)
        self.head=temp

    def find_nth_2_last(self,n):
        current=self.head
        sec_pointer=self.head
        count=1
        while current is not None and count            current=current.getNext()
            count +=1
        while current.getNext() is not None:
            current=current.getNext()
            sec_pointer=sec_pointer.getNext()
        return sec_pointer.getData()

mylist = UnorderedList()
mylist.add(7)
mylist.add(6)
mylist.add(5)
mylist.add(4)
mylist.add(3)
mylist.add(2)
mylist.add(1)

print mylist.find_nth_2_last(4)

Write code to remove duplicates from an unsorted linked list.

__author__ = 'nitin'

class Node:
    def __init__(self,initdata):
        self.data=initdata
        self.next=None
    def getData(self):
        return self.data
    def setData(self,item):
        self.data=item
    def getNext(self):
        return self.next
    def setNext(self,item):
        self.next=item

class UnorderedList:
    def __init__(self):
        self.head=None

    def isEmpty(self):
        return self.head==None

    def add(self,item):
        temp=Node(item)
        temp.setNext(self.head)
        self.head=temp

    def size(self):
        current=self.head
        count=0
        while current!=None:
            count=count+1
            current=current.getNext()
        return count

    def rem_duplicates(self):
        current=self.head
        result=self.head
        print_list(result)
        print "\n"
        while current!=None:
            iter_node=current.getNext()
            prev=current
            while iter_node!=None:
                if current.getData()==iter_node.getData():
                    prev.setNext(iter_node.getNext())
                else:
                    prev=iter_node
                iter_node=iter_node.getNext()
            current=current.getNext()
        print_list(result)
        return result

def print_list(result):
    current=result
    nxt = current.getNext()
    print current.getData()
    if(nxt is not None):
        print_list(nxt)

mylist = UnorderedList()
mylist.add(7)
mylist.add(6)
mylist.add(5)
mylist.add(4)
mylist.add(3)
mylist.add(5)
mylist.add(2)
mylist.add(1)

print result=mylist.rem_duplicates()