Day 24: More Linked Lists

• Instructions:
  • A Node object has an integer data field, data, and a Node instance pointer, next, pointing to another node (i.e.: the next node in a list).
  • A removeDuplicates function is declared in your editor, which takes a pointer to the node of a linked list as a parameter.
  • Complete removeDuplicates so that it deletes any duplicate nodes from the list and returns the head of the updated list.
  • The first line of input contains an integer, N, the number of nodes to be inserted.
  • The N subsequent lines each contain an integer describing the data value of a node being inserted at the list’s tail.
  • Contraint:
    • The data elements of the linked list argument will always be in non-decreasing order.

Excercise

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class Node:
    def __init__(self,data):
        self.data = data
        self.next = None 
class Solution: 
    def insert(self,head,data):
            p = Node(data)           
            if head==None:
                head=p
            elif head.next==None:
                head.next=p
            else:
                start=head
                while(start.next!=None):
                    start=start.next
                start.next=p
            return head  
    def display(self,head):
        current = head
        while current:
            print(current.data,end=' ')
            current = current.next

    def removeDuplicates(self,head):
        #Write your code here

mylist= Solution()
T=int(input())
head=None
for i in range(T):
    data=int(input())
    head=mylist.insert(head,data)    
head=mylist.removeDuplicates(head)
mylist.display(head); 

Solution

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class Node:
    def __init__(self,data):
        self.data = data
        self.next = None 
class Solution: 
    def insert(self,head,data):
            p = Node(data)           
            if head==None:
                head=p
            elif head.next==None:
                head.next=p
            else:
                start=head
                while(start.next!=None):
                    start=start.next
                start.next=p
            return head  
    def display(self,head):
        current = head
        while current:
            print(current.data,end=' ')
            current = current.next

    def removeDuplicates(self,head):
        current = head
        while current:
            if current.next != None:
                if current.next.data != current.data:
                    current = current.next
                else:
                    next_node = current.next.next
                    current.next = None
                    current.next = next_node
            else:
                return head
            
mylist= Solution()
T=int(input())
head=None
for i in range(T):
    data=int(input())
    head=mylist.insert(head,data)    
head=mylist.removeDuplicates(head)
mylist.display(head);