Remove Duplicates From Linked List - Cracking the Coding Interview, Leetcode

This problem appears in both Cracking the Cracking Interview and Leetcode. The problem is this: given a linked list, delete duplicates such that each number appears only once.

For example:

input: 1 -> 1 -> 2
output: 1 -> 2

Here's a hint. Use a hashset to store your unique numbers in, and if the number exists already in the hashset, set the pointer of the previous node equal to the next node of current node.

class Node:
  self.data = data
  self.next = None

class Solution:
  def removeDuplicates(self, head:Node) -> Node:
      hashSet = set()
      node = head
      prev = None
      while node:
         if node.data not in hashSet:
            hashSet.add(node.data)
            prev = node
         else:
            prev.next = node.next
          node = node.next
      return head

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Remove Duplicates From Linked List - Cracking the Coding Interview, Leetcode

Shirley

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