CA 23 - Remove Duplicates in Sorted Linked List

Problem Statement: here

Solution:

• The list is already sorted, so duplicate values will always appear next to each other.
• Start from the head of the linked list and look at one node at a time.
• For each node, compare its value with the value of the next node.
• If both values are the same, it means a duplicate is found.
• Instead of keeping both, adjust the link so that the current node skips the duplicate and points directly to the next different node.
• If the values are different, simply move to the next node and continue checking.
• Repeat this process for the entire list until the end is reached.
• By doing this, all duplicate nodes are removed without using any extra space, and only unique elements remain in the list.

def removeDuplicates(head):
    curr = head
    while curr and curr.next:
        if curr.val == curr.next.val:
            curr.next = curr.next.next
        else:
            curr = curr.next
    return head