URL : https://www.hackerrank.com/challenges/30-linked-list-deletion/problem
- Objective
- Check out the Tutorial tab for learning materials and an instructional video!
- Task
A Node class is provided for you in the editor. 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 head 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.
Note: The head pointer may be null, indicating that the list is empty. Be sure to reset your next pointer when performing deletions to avoid breaking the list.
- Input Format
- You do not need to read any input from stdin. The following input is handled by the locked stub code and passed to the removeDuplicates function:
- The first line 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.
- Constraints
- The data elements of the linked list argument will always be in non-decreasing order.
- Output Format
- Your removeDuplicates function should return the head of the updated linked list. The locked stub code in your editor will print the returned list to stdout.
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def removeDuplicates(self,head):
#Write your code here
if head is None:
return None
ls = [head.data]
node = head
while node.next is not None:
if node.next.data not in ls:
node = node.next
else :
snode = node.next
node.next = snode.next
del snode
ls.append(node.data)
return head