There is definitely a pattern! Sorted array, and previously move zeros. Well this has no relation to the remove-zeros, but it’s interesting….

This suggests an interesting lesson as well, three variations on a theme. That’s why I’m doing these things.

class Solution(object):
    def deleteDuplicates(self, head):
        if head is None:
            return head
        curr = head
        while curr is not None and curr.next is not None:
            while curr.next is not None and curr.val == curr.next.val:
                curr.next = curr.next.next
            curr = curr.next
        return head

I bet there’s a nicer way of writing that loop. It’s interesting that this logic “feels” neater to me (especially if my suspicion of a nicer way of writing that loop bears out.)

Nested loops with linked lists! Neat.